Monday, January 8, 2018

Bière de Saison (1905) recipe - infusion mash

Compared to other beers (like lambic, grisette and Bière de Garde), I haven't said much about historic saison on this blog. So it's probably time I do a bit of that. Two fairly complete recipes are given for "bières de saison" in the Q&A sections of the 1905 Petit Journal du Brasseur. In both cases, the brewer describes their process in detail and asks for advice on this proposed process to make these beers. One of brewers wants to brew by infusion and the other by a form of turbid mashing. On the whole the recipes have similarities but I think it is worth presenting both in full as the two give a good idea how brewers were approaching these beers at the time - both in their similarities and their differences.

Question about a bière de saison in PJB 1905.
In this first post I'll address the infusion recipe as well as some background/context, with the turbid mash recipe and some comparison saved for a post to come.

Though the breweries aren't named, from the publication and the text it is clear that these are somewhat industrial brewers rather than the rustic farmhouse notion of saison (in the same way that modern saison breweries are generally not really farmhouse breweries but industrial breweries, some of which happen to be around farms). In that sense though, I think these recipes show an important point in the history of saison. They come at a time when the beers were still brewed in the winter and served in the summer and were still mixed-culture beers, but also when the beer had moved to commercial breweries as a component of their production instead of the lore of an off-season brew at a farm. So in that way they offer a point of connection between modern saison and the origins of saison, and they may fall close, in spirit at least, to the modern mixed-culture saisons.

I feel like I should also say something about the use of the term bière de garde here (although I've also discussed this in other posts recently). Both brewers call the beers they want to make a bière de saison and then clarify in parentheses a bière de garde. Bière de garde is used in a general sense here to mean a beer for aging, with bière de saison being a bit more of a specific name, but this shows the fluidity of both of these names for Belgian beer at the time. With that said, the recipe, process and advice given for these beers is quite similar in many ways to the sort of considerations taken when making Bières de Garde from the north of France.

These recipes both use "Escourgeon". I've talked about this elsewhere and it shows up in other places such as the saison history chapter of Farmhouse Ales. If you are unfamiliar with this grain, it is winter 6-row barley. In the 1800s and early 1900s Belgium was growing and using 6-row barley more or less exclusively. Escourgeon is frequently the recommended barley for beers for aging, though it may have been harsher than spring 6-row barley in younger beers. Within Escourgeon there was also a hierarchy, with certain regions preferred over others. In general, Escourgeon would have had a higher protein content than modern grains. With proper malting and mashing, this would mean more darkening (and the sort of flavor development that goes along with this) in kilning and boiling.

One final general point about these recipes - neither one of these recipes discusses the flavor profile of the finished beer or if the fermentation was "pure culture". But, given the time and the nature of beer (ale fermentation), they were likely mixed culture beers. What exactly that means would have varied from brewery to brewery, but it likely included some atypical Saccharomyces strains or non-Saccharomyces yeasts (so possibly Brett and/or other yeasts that you might find in other Belgian mixed culture beers) as well as the potential for bacteria. Both beers are reasonably hopped - around or above modern lambic levels (though this is not really a good comparison as one case deals with fresh hops from 100+ years ago that may not grown anymore and the other deals with aged modern hops).

Open-topped mash tuns, like this one at
Brasserie à Vapeur, can lose a lot of heat.
It is possible that in the time scale of around 5 months, some bières de saison may not have developed a lot of acidity. But I would guess that many would have, given acidity in other comparable beers like Bière de Garde, other discussions in PJB about acidic saisons and PJB discussions about customer taste preferences. So, for the modern brewer looking to brew something based off of this, using a mixed culture with multiple yeasts as well as lactic acid bacteria would be a good way to go.

OG: 1.049-1.051
100% Escourgeon Malt
Hops from Poperinge - 3.1 kg per 100 kg grain, ~450 g/HL wort pre-boil. The varietal is not specified. Hopping is discussed below in more detail.

  1. Mix water at 60-62° C (140-143.6° F) with the grain reach 52-55° C (125.6-131° F) in the mash tun. Mix for 20 minutes and then rest for 10-15 minutes.
  2. Infuse with water at 90° C to boiling to raise the temperature to 70-71° C (158-159.8° F). Rest 1.5 hours.
  3. Collect wort from the initial saccharification rest into the boil kettle.
  4. Infuse with water at 76-85° C (168.8-185° F) such that the mash temperature remains at 70-72° C (158-161.6° F). Mix for 20 minutes and then rest for 30 minutes.
  5. Collect wort from the second saccharification rest into the boil kettle.
  6. Sparge with water at around 75° C (167° F), or perhaps slightly warmer.
The old Brasserie Dupont mash tun.
There are some general things to keep in mind with this info regarding the temperatures of the added water and the resulting mash temperatures. A typical mash tun of the time would have been an open-topped iron mash tun with an aspect ratio sort of like a hockey puck or tuna can rather than something with closer to a 1:1 width to height ratio or more like a soup can (as is more typical of modern equipment). These ~1900 Belgian mash tuns could have lost a good deal of heat over the course of a mash rest (possibly around 2° C / 3.6° F per 30 minutes as mentioned in this post). Additionally, the infusion water is heating both the grain and the thick iron mash tun, and the latter would take a lot of heat to warm it up compared to modern equipment. Therefore, attempting to mash like this on a home scale or with modern commercial equipment might require some adjustments of the infusion water (smaller volumes or cooler water).

Hop fields in Poperinge.
Boil and hopping
The boil lasted 5 hours. The hopping was as follows:
  • First wort hopping:
    • 10% of the hops after the first mash runnings were collected
    • 10% of the hops when all of the wort has been collected but before the boil starts
  • Hops in the boil
    • 40% of the hops after boiling for one hour
    • 40% of the hops one hour before the boil ends (or 4 hours into the boil)
As noted above, the hops used in this recipe came from the Poperinge region, one of the two main regions of historic Belgian hop growing (and the main region for modern-day Belgian hop growing). The landrace Belgian varieties grown at this time (e.g. Coigneau, Buvrinnes / Tige Vert / Duitsche Hop / Tige Allemande, Groene Bel / Cloche Vert, Tige Blanche / Witte Ranke, Tige Rouge / Roode Rank) have more or less disappeared, though some varieties have been re-discovered and are seeing small-scale cultivation starting up.

Belgian hops were believed to be a bit less potent than contemporaneous German and Czech hops (for a bit more info comparing hops from different regions in the late 1800s and early 1900s, see the table in this blog post), and it is also likely that advances in hop farming could result in higher alpha acids in modern hops than historic hops. For the modern brewer, landrace French hops may be a good choice, or German or Czech hops at a slightly lower hopping rate than the one quoted here.

The final volume isn't noted in the Q&A so I'm not sure exactly what the final hopping rate would be in terms of g per HL. Based on the pre-boil volume given (45 HL) and the process (5 hour boil, maybe cooling in coolships or maybe not), and similar modern breweries (lambic brewing) I'm going to estimate that this is roughly 530 to 630 g per HL of wort in the fermenter, depending on if a coolship is used or the wort is force-cooled.

The old (and long out of use) coolship at Brasserie à Vapeur.
Fermentation and aging
Yeast was pitched when the beer was 21° C / 70° F (nothing is said about the method of cooling, but coolships or a cooling system like a Baudelot chiller would have been appropriate). It sounds like fermentation at this specific brewery took place in a metal tank - perhaps something like what is shown below. But the beer was then aged for around 5 months, likely in wooden barrels.

Modern homebrew adaptation
Here is an approximation for adapting this to modern ingredients and at homebrew sizes. Feel free to make your own adaptations from the historic recipe. I haven't yet tried to brew something like this myself, so this is a theoretical recipe and could have some kinks to work out.

Batch size: 19 L (5 gal) pre-fermentation wort
OG: 1.050
ABV: ~6%
IBU (theoretical, Tinseth): 35
Total Efficiency: 75%

Open fermentation in a metal tank at De Dolle.
4.1 kg (9.0 lb) Continental European Pale malt. Go for something like Dingemans, Chateau, or Soufflet/Franco-Belges if you want a bit more color or something like Weyermann and Best is you want it to be a bit paler.

100 g Strisselspalt, 2% aa (other another low aa landrace hop, you may want to adjust the 4 hr boil addition a bit based on aa if you swap to another hop)

Mash: This follows the mash above, but you should probably rerun the infusion temperature and volume calculations as this could vary a bit based on your system. Keeping extra boiling water and extra cold water on hand in case you need to quickly adjust the mash temperature is probably good too. I think this is good in general, especially with new or complicated/strange mash schedules.
  1. Mix grain with 7.7 L of water at 60.6° C (8.1 qt at 141° F) to reach 53° C (127.4° F). 10 minutes total for adding the water and mixing. Rest for 20 minutes.
  2. Slowly infuse 8.1 L of water at 89° C (8.6 qt at 192.3° F) to reach a mash temperature of 70° C (158° F). Take 10-20 minutes for the rise, so maybe add the volume in small steps rather than all at once. Rest for 1.5 hours. This step could probably be shortened a bit with modern conditions.
  3. Drain the mash into the boil kettle. Keep this wort on low heat (intermittently if necessary) so that it stays between 75° C and boiling. I'm guessing the volume in the boil kettle should be around 12.4 L (3.25 gal) based on a grain absorption of around 4.2 L (~1.1 gal) and with a bit of extra wort remaining behind from false bottom dead space, etc. The remaining calculations are based on this figure.
  4. Infuse with 15.5 L at 71.7° C (16.4 qt at 161° F). The total time for the addition and mixing should be around 10 minutes. The rest for 30 minutes. This step could also probably be shortened with modern grain/equipment.
  5. Drain the wort and sparge (fly or batch, as you prefer) with water at 75° C (167° F).
Boil: 5 hour boil. For me that would mean starting with about 42.6 L (11.25 gal) assuming 3.8 L (1 gal) per hour boil off and 3.8 L (1 gal) loss to trub. Begin heating to a boil after the second mash wort is collected or, if fly sparging, shortly after you begin sparging.
  • First wort hop: 20 g, split evenly between hops added after the first wort is collected and once the wort from the second mash is collected.
  • 40 g hops after 1 hour of boiling.
  • 40 g of hops after 4 hours of boiling / with 1 hour left in the boil.
Either chill by using your boil kettle as a coolship or as you would normally chill your wort. If you go the coolship route this will likely change the extraction from the hops. If you have another kettle/vessel to use as a coolship then you could transfer off the hops into that when you begin cooling.

Fermentation: Pitch a mixed culture that you like including multiple yeasts and bacteria. I tend to keep around dregs of various commercial beers that I like along with a saison strain and some brett isolates/blends, so I'd probably use a combination of these (e.g. a saison strain or two that I like co-pitched with a brett isolate or brett blend that I like along with the dregs of commercial barrel aged saisons and/or lambics that I like all together for primary). Pitch the yeast around 20° C (68° F) and let free rise, or possible help it rise. The exact profile you follow will depend on which saison strains you choose.

Age for about 5-6 months, or until gravity is stable and you like the character. I see no reason to rack to a new vessel for the aging, so I'd just leave it in the primary fermenter if your primary is fairly air-tight (glass or stainless). Wood would also be fine if you have a good barrel, though I'd lean toward larger barrels if you go this route. I know small  barrels can work out well for some, but I've tasted a lot more disappointing beers from small barrels (too much oak/barrel character or too much O2) than good ones. Then bottle (or keg, if that's your preference - I'm partial to bottling), keeping in mind final gravity stability to avoid over-carbonation problems.

Monday, December 18, 2017

Brief Translations Compiled

From time to time I'll put some of the quick translation work that I'm doing on the blog's FB page. These are usually snippets of articles/books or quick Q&A sections from Petit Journal du Brasseur. I feel that these posts don't warrant their own full blog post (at least not at this stage), but I still find them interesting so I want to share them somewhere. The downside of doing this on FB is that they are quickly lost and tricky to retrieve. So I've decided to catalog them here in this blog post so that anyone (myself included) can easily find them and look back at them.

A question about brewing a beer for aging (PJB 1910).
Some new old brewing information:
In addition, I thought I should add something new, so here's a new snippet of something quick - the sort of thing that I'd usually put on the FB page. This comes from Petit Journal du Brasseur in 1910, where a brewer is asking about brewing a bière de garde with an OG of 1.055 for serving in summer (note that bière de garde is used here as a general term for an aged beer, not for the French category Bière de Garde). The advice follows general advice for this sort of beer for the time (for example, suggesting 100% barley malt, though as the gravity is above 1.050 perhaps some unmalted grain could be used) but with some good insight.

I think the discussion of hopping is a good section to highlight here as there are a couple important points. First, they note hopping rates need to be sufficiently high for the beer and suggest at least 20 kg for 812 kg of grain. This hopping rate is pretty high (on the order of 50% higher than lambic at some modern breweries). Unfortunately the batch size isn't given, but making efficiency assumptions based on other beers of the time, this is probably roughly a hopping rate of 500 g/HL (an earlier version mistakenly said 500g/L, see the hopping table in this post for notes on conversion factors here). This highlights the importance that brewers of the time placed on hopping beers for aging at elevated rates.

Second, there is discussion of using hops of multiple years. So potentially a brewer could be using aged hops in their beer, but the volume of aged hops suggested would be roughly doubled to replace a portion of hops from the most recent harvest. I like the information here regarding aged hops v. fresh for hopping rates as well as the context that the information gives - brewers may or may not be using aged hops for beers destined for aging that weren't lambic. Finally, the post discusses the possibility of using hops from Oregon. The use of US hops shows up elsewhere at this time in Belgium but I don't think I've talked about it before. So this is a good time to point out that US hops were used by some brewers in Belgium in the early 1900s.

Mention of hopping rates, age and origin (PJB 1910).

Links to the previous FB posts:
Here is a compiled list of posts from the blog's FB page. This is organized by topic, with the original source and posting date, and any other notes. I'll try to remember to update it as I post more on the FB page.

Lambic, Faro, Bière de Mars, Geuze:
Saison and Belgian bière de garde:
(As noted above, there bière de garde can mean different things. The differentiation of the Francophone Belgian use of the term bière de garde and this term used to describe distinct beers from the North of France is discussed a bit more in this blog post)

Monday, November 20, 2017

Brewing Bières de Garde (1850-1910)

Following up on this blog post giving background info on Bière de Garde and French brewing around 1900, this post gets into the brewing side of historic Bière de Garde. As noted in the background post, these beers are distinct from the modern northern French beers of the same name. As a brief comment on the modern side, I learned recently from Daniel Thiriez of Brasserie Thiriez that there is a new (well, ~1 year old) French law regarding what can be called a Bière de Garde - the beers now must be aged a minimum of 21 days after primary. We agreed that this law seems to be a bit toothless and quite broad, as there is no recipe restriction, etc. And 21 days is a far cry from the 6+ months of aging for Bière de Garde from around 1900.

Bière de Garde advertisement from the early 1900s.
From the collection of D. Thiriez.
The information for this post is a synthesis of 9 texts from 1850 to the early 1900s. These texts present a view from more established breweries, and spanning the time from the height of Bière de Garde to near when the original long-aged mixed culture versions disappeared. While each of the texts has small differences from the others, the general nature of the beer remains the same - a roughly amber colored beer of mixed fermentation with a moderate hopping and which is allowed to become acidic and vinous over 6+ months of aging.

The grist composition of Bière de Garde was 100% malted barley which, for the time, was kilned using older methods. Direct heat was used and that the malt came out slightly toward amber. I think something along the lines of a continental European Pale Ale malt is about right given the descriptions of the final beer color and the process. The recommended barley was the Escourgeon, or winter 6-row barley. This was the common grain for much the area (across Belgium you often see the same recommendation) and it could be a bit of a sharp or coarse malt. Escourgeon had more polyphenols and higher nitrogen levels, which would help to develop more melanoidin compounds in kilning and boiling. This sort of malt wasn't great for softer or quicker turnaround beers, but it was well suited for aged beers.

Hops for Bière de Garde were primarily coming from the Nord region or Belgium. These hops were of more standard quality. This may present a bit of a challenge to the modern brewer, but French landrace hops may be a good place to start. Some sources also mention a portion of higher quality hops coming from Bavaria, Bohemia, or other regions of France, so this gives modern brewers some more options.

Yeast was pitched for Bière de Garde, and based on the descriptions of the final beers it was a mixed culture involving at least Brettanomyces and lactic acid bacteria in addition to Saccharomyces. Figuier, quoting Müller (1873), notes that Bière de Garde, and in general the beers of this region, had a vinous quality and that this quality was sought by locals.

General Specifications
Bière de Garde is described as an golden-amber or brown beer (sometimes both by the same source, suggesting that "brown" may have been used more generally or encompassed a wider range than it does now). Either way, from this I suspect the beers were generally not toward the darker side of brown, and a pale amber may be a better description for the modern brewer/beer drinker. The paler side of amber seems to fit better with the above photo. Though I'll note that the original of that print was from 1930, and therefore after Bière de Garde as discussed here had mostly (if not fully) vanished.

This table (below), modified slightly from a similar one posted a couple weeks ago on the blog's FB page, shows the parameters of ~1900 Bière de Garde alongside 1970s & modern lambic and geuze as well as modern Flanders acidic ales. Taking these 5 examples of Bière de Garde, the OG that one could expect around 1900 was roughly 1.045. This sounds a little low to me, so I wouldn't be surprised if gravities that were a bit higher (~1.050-1.055) were also brewed. But I haven't seen other gravities listed so far. With a very high attenuation, the alcohol of these examples generally comes out to around 6% ABV.

The acidity of the beers was fairly high, both in lactic and acetic acidity. On the whole the acid profiles compare well with Flanders acidic ales before they are blended back with younger beer for packaging, though BdG was a bit lower in lactic acid than these Flanders beers. And the acidity also compares well with more sharp lambics, but when averaging across multiple producers from the 1970s, ~1900 BdG is higher in both lactic and acetic acid.

A comparison of ~1900 Bière de Garde with some modern aged acidic beers.

Brewing Process
Mashing: Bière de Garde used a type of turbid mashing. Although only a few turbid mash schedules are known today, and only for a small range of beers, different schedules of turbid mashing were employed for a wide range of beers in Belgium and northern France. And there were many more versions of turbid mashing than remain in modern brewing (though even today there are still differences among lambic brewers about the specific rests, number of turbid pulls, and when the turbid wort is added back). The different Bière de Garde texts that I've seen all more or less describe the same sort of mash, with 3 temperature rests and one turbid pull:

-An initial infusion is conducted. Some texts have this rest temperature quite cool (25-35 C, some even lower than this) and others have it higher, in the protein conversion range.
-After the first rest, the wort is drained off and heated to a boil in a secondary boil kettle. This is the one turbid pull used in Bière de Garde mashing.
-Hot water (somewhere from 80 C to boiling) is added back to the grain bed to raise the temperature to the cooler end of the saccharification range. The mash rests here for a while.
-Wort is extracted and transferred to the primary boil kettle. Now the turbid wort which has been boiled comes back to the grain, and an additional saccharification step is now carried out with this wort.
-After the second saccharification this wort is combined with the earlier mash runnings in the primary boil kettle.
-The grain bed is sparged, more or less as normal, though much of this wort is used for table beers rather than Bière de Garde.

Here are a couple mash schemes from historic texts. First is a scheme based on the information in Bauby & Fournier (1868), taking into account the mashing that Bauby & Fournier report, the modifications they suggest, and filling in some gaps with reasoning and similar general schemes described by other sources. The second is a reproduction of the mashing scheme I presented in this blog post, which originally comes from Evans (1905). A couple of sources I looked at have the initial rest closer to 50 C rather than the cool starts of both of these mashes. But otherwise these other mashes follow a similar remaining process to these two. Finally, for reading the figures below, blue arrows represent transfer of liquid (removal of turbid wort, infusions, collecting final wort).

A mashing scheme based off of Bauby & Fournier (1868).
There are a couple general things to keep in mind with these mashing schemes. First, these mashes reflect non-modern conditions. Rest times could probably be shortened a bit if you wanted to try these yourself. Also, with the sort of equipment used in these breweries at this time, there was a much larger heat loss to the vessels than with modern equipment when raising the mash temperature. Additionally, it would not be uncommon to have an open topped mash tun, which would also lose a good deal of heat. Jean-Louis Dits of Brasserie à Vapeur has such a mash tun, and he reported temperature drops of up to 2 C per 30 minutes (see this post for more info about their mashing). So if you want to try one of these mashes yourself, you may want to lower the infusion temps to hit your targets and keep extra cold water around in case you overshoot. Finally, not everything is specified with these mashes to the extent that I would like (especially in the mash based on Bauby & Fournier). I have tried to fill in the gaps with what is reasonable given the mash process up to that point, expected heat loss, and what the wort would need to be like. And I have tried to present the remaining uncertainty to these assumptions.

The mashing scheme presented in Evans (1905).

Boiling: Bière de Garde underwent a long boiling. The sources agree on at least a 5 hour boil, with many mentioning boils lasting up to 8-10 hours. Considering this, the gravity is fairly moderate at around 1.040-1.050. The English brewers discussing the boil in Evans (1905) also note that they were surprised that the boil did not darken the beers as much as they expected.

Hopping rates were around 4-5 g/L (0.53-0.67 oz/gal), with some sources mentioning rates slightly above and below this. Some sources say that hops were added right at the start of the boil while others say hops were "only" boiled for a couple hours. So either way hops underwent a long boil of multiple hours. Some hops, especially if higher quality hops were used, may have been reserved for later in the boil. But overall this isn't discussed much in these texts

At the end of the boil the beers were cooled in coolships.

Fermentation: As noted above, Bière de Garde was pitched with a mixed culture, though at a lower rate than would have been common for most beers at the time. Fermentation began somewhere from around 20-25 C. Some later sources note the temperature may have started a bit cooler (~17-21 C). The beers were fermented in casks, generally the same casks as used for transport, and active fermentation took around 3 days. Following the primary fermentation, the beers were aged for around 6 months or more, during which time the beers developed acidity and vinous character.

Closing thoughts:
Having discussed BdG recipe and process, I think it is noteworthy that the descriptions of French Bière de Garde are quite similar to the descriptions of Saison in Belgian sources from around the same time. Suggested malts, mashing process, hops, boiling time, etc. are in general basically the same for these two beers. This is not surprising given that the Nord department borders the Hainaut province and that the beers share similar origin lore, but I think it is worth pointing out anyway.

Something to think of when
considering historic Bière de Garde?
Finally, I think it may be helpful to contextualize historic Bière de Garde by considering Cantillon's Iris. Perhaps this is a bit of a tired reference. When considering the above BdG-Saison comparison, I know I frequently say something to this effect and it is also in the De Baets chapter on Saison history in Farmhouse Ales. But I think the similarities are sufficient to bring it up again. Both are 100% malted barley (even more so - malt of about the right color) and also turbid mashed. The hopping rates are similar (though BdG was hopped a bit more and Iris is dry hopped). They both have a long boil and then are cooled in a coolship. Of course there are the important differences that Iris is spontaneously fermented while BdG was pitched with a mixed culture, Iris uses some aged hops, and Iris is aged longer. But still I think Iris probably falls closer to ~1900 BdG than many other modern beers would.

This wraps up a historic Bière de Garde brewday. Hopefully you found that informative, and it helped to differentiate the modern and historic (1850-1910) beers using this name. Here are links to other posts on the blog discussing Bière de Garde, both of which are also linked in the text above:

-Thoughts on Evans, 1905
-Introductory thoughts on BdG

Lacambre (1851). Traité Complet de le Fabrication des Bières...
Bauby & Fournier (1868). Guide Raisonné de la Fabrication de la Bière.
Figuier (sometime in the 1870s, I'm not sure of the exact date). Les Merveilles de l'Industrtie...
Cartuyvels & Stammer (1879). Traité Complet Théorique et Pratique de le Fabrication de la Bière et du Malt
Boulin (1889). Manuel Pratique de la Fabrication de la Bière.
Moreau & Levy (1905). Traité Complet de le Fabrication des Bières...
Evans (1905). The Beers and Brewing Systems of Northern France.
Petit Journal du Brasseur (1910).
Mulo (I don't know the year). Brasseur ou Art de Faire Toutes Sortes de Bières.
Thanks also to Daniel Thiriez and Yvan De Baets for conversations that helped with organizing my thoughts about these beers.

Wednesday, October 25, 2017

Introductory thoughts on Bière de Garde

For the past couple years I have been somewhat passively researching Bière de Garde and I think the time has come for me to start being a bit more active about putting this info together into blog posts. Before getting into the brewing side I wanted to start with this an introductory/general post to address terminology and the setting for the beer. For clarity throughout this post, I'll use capitalized "Bière de Garde" to refer to the specific family of beers from the north of France and I'll use lower case "bière de garde" when using the term to more generally refer to aged beers. If this doesn't make sense, it should shortly.

The term Bière de Garde
A question regarding brewing a bière de garde from Ghent.
(Petit Journal du Brasseur, 1901).
Discussion of bière de garde from Augsburg and Munich, Lacambre (1851).
I find Bière de Garde to be one of the trickier families of beer to discuss based on the wide range of what this name can mean. To the non-Francophone beer world this term likely refers fairly unambiguously to a distinct (though still stylistically open) category of beers from the Nord and Pas de Calais departments of northern France. But the non-Francophone beer world might not be as familiar with this term to apply generally to a diverse category of aged beers, using the term for its literal meaning (beers for keeping/storage, or since this part has been done already by the brewer, beers that have been kept). The historic Belgian brewing literature regularly uses this term to discuss general beers designed to be aged. And these beers could cover quite a range of strengths, ingredients, and brewing styles. In the modern world I think bière de garde is used less generally, but when looking through the historic texts the French Bières de Garde are definitely in the minority of the uses of this term.

Just as the French-language brewing literature may use the term bière de garde to refer to beers unrelated to historic Bières de Garde, the modern beers bearing this name as a category are also fairly unrelated to the historic category. There is a discontinuity not only temporally between the historic mixed culture Bières de Garde that were found until the early 1900s and the modern range of beers bearing this name, but also in process and ingredients. For the rest of this post I'll generally be discussing historic Bières de Garde, focusing on the period between industrialization of breweries and when the historic versions disappeared in the early 1900s. For those interested in the rebirth of the name and the modern iterations, Farmhouse Ales (by Markowski) and The Beers of Northern France by Rigley and Woods give a good idea of the story and the range of producers. The former should already at least be on the list of any Anglophone brewer interested in Bière de Garde and saison, if not already read and re-read multiple times. While the latter is a bit dated, it can be found (at least now) for ~5 USD / EUR. It is certainly worth that if you're interested in French beer.

Recommended reading for modern Bière de Garde.
Brewing in France before the 1900s and brewers of Bière de Garde
While France may not have had always the beer focus of some of its neighbors, many distinct regional beers were brewed in the 1800s and earlier. Around 1850, Lacambre (Traite Complet de le Fabrication des Bières..., 1851) describes distinct regional ales from Paris, Strasbourg and Lyon in addition to the beers of Lille. I should note that Bière de Garde is generally discussed under the category of beers of Lille in the historic texts I've seen (Lille is the most prominent city of the Nord department). I am combining Nord and Pas-de-Calais for this discussion as modern Bière de Garde brewers can be found in both departments. But most of the historic documents I've seen mention Lille, and possibly the Nord in general, as the region for Bière de Garde without addressing Pas-de-Calais.

This diversity of regional beers seems to have changed quickly, as Figuier (Les Merveilles de l'Industrie, published in the 1870s) notes that Paris had switched rapidly to lager brewing starting in the late 1860s, modeling their beers after those from Bavaria and Vienna. During this time the brewers of Lille continued to produce their beers of top fermentation - these including Bière de Garde as well as an ordinary brown beer (which was served young) and table beers. In addition, some brewers produced a white beer (which I've written about here), though this was not very common.

A map showing the he Nord and Pas-de-Calais departments of
Northern France, western Belgium and some larger cities.
The resilience of the north, though strong, was unfortunately not enough to preserve these beers. Evans (1905) and Moreau and Levy (also 1905) both note that few regions of France were still producing top fermentation beers in 1905. And Evans notes that Bière de Garde was rapidly becoming less popular, having fallen from 50% of the consumption of Lille in 1900 to less than 20% in 1905.  With Bière de Garde already on the back foot, WWI was pretty much the end of the style. As I've written about a bit in this post, the devastation the region faced and the way this put additional pressure on breweries (loss of life, loss of equipment, insufficient crops to maintain production, etc.) resulted in a significant loss of breweries and the regional beer identity compared to before the war. This basically signals the end of traditional Bière de Garde production.

The table below shows brewing trends in the north of France in the early 1900s (the number of breweries and production volume, in degrees-hectoliters). This is presented for both the Nord department alone as well as the 5 northern departments of France that were more prominent beers regions (including Nord and Pas-de-Calais). While the date coverage is a bit spotty, there is a clear difference between the early 1900s (before WWI), where production and brewery numbers seem fairly stable and the 1930s. Other 1930s data as presented in Petit Journal du Brasseur 1939 are generally similar, though a decline in the number of breweries and some variability in total production are seen during the 1930s. 1939 was chosen for this comparison and it included both the number of breweries and the production volume for the same year.

Some quick data on the breweries and production levels in Northern France in the early 1900s.
The Bière de Garde revival, with distinctly different beers from the original Bières de Garde, begins roughly 10-50 years after this, depending on who you credit. Jenlain claims to have been the first among the new brewers to use the name Bière de Garde for their ale aged a couple weeks in tanks in the 1920s. Castelain employed the title in the 1970s for their lager CH'TI, also aged for weeks rather than months. It was not until around the 1970s and later that the name caught on to mean a new category of northern French beers.

General characteristics of historic Bière de Garde
A few points are clear about the general nature of historic Bières de Garde. They were turbid mashed, as is discussed in this blog post. Additionally the beers were top fermentation mixed culture beers. And, given that they were aged for many months, they had some chance to express this character. This is in strong contrast to modern versions, where the beers may be lagers or fairly neutral ales (as well as ales with a bit more fermentation character) which are generally aged a couple additional weeks.

This is sort of a strange contrast between the two Bières de Garde (along with some process differences that I'll get into in a future post), and makes them in effect two unrelated products. I think using the term bière de garde to refer to a beer with a bit more aging in the process is fine. And the modern use of the term does denote a specific category of beers (varied though that category may be, and although the aging is fairly short). But I think making a tie between the historic and modern beers of this name is tenuous at best. Perhaps it is better to brew the beer you like, call it something that makes sense and communicates what it is, and let the beer be just a beer without trying to invoke the historic lore of a beer brewed with fundamentally different ingredients and substantially different methods on different equipment.

Alright, so this gives a bit of an intro into Bière de Garde - where it came from, when it was produced and differences between the historic and modern versions. I'm working on synthesizing recipes and process to put together a post detailing brewing these beers. I've already let a bit of that info out in the form of this post on the blog's facebook page, showing the OG, FG and acid profiles of Bière de Garde from around 1900 as well as modern lambic and Flanders acidic ale. Hopefully I'll have a brewing process/recipe-focused post within the next couple weeks.

Monday, August 28, 2017

Spontaneous fermentation barrel fill

This post details the first spontaneous beer I have fermenting in oak. It is in a 225 L / 60 gallon barrel that I co-own with some friends, and so far it is progressing nicely. We filled this barrel with one big brew day - a turbid mashed brew taking inspiration from lambic production - using a bunch of our homebrew equipment pooled together.

I'll focus mostly on our decision taking for this approach to the barrel rather than a solera-type approach and cleaning the barrel, but I'll also include more typical brewday stuff (our plan, recipe, process, etc).

The barrel needing a bit of touching up, accomplished here
with a heat gun, beeswax and something like a putty knife.
The barrel
I've mentioned the origins of this barrel in this blog post. Since November 2014 this barrel has been full of a homebrew solera-type project. The initial fill was a saison with brett and Lactobacillus. After about 7 months we pulled off ~1/3 and re-filled with young (<1 month old) beer that was turbid mashed, open cooled and then pitched with various cultures (dregs, ambient wild microbes and lab cultures). A second partial empty and refill was done 14 months later, again with lambic-inspired young beer (and one portion was spontaneous this time).

Since the initial fill, we felt that the beer wasn't really progressing the way we wanted. The end goal was something lambic-inspired and the group that shares the barrel has had a growing interest in spontaneous fermentation. But the partial re-fills with young beer weren't really pushing us in that direction as much as we liked. The beers coming out had increasing acidity, approaching levels beyond our goals for a balanced product, and the flavor complexity wasn't really developing as we wanted. Maybe this is influenced by the pretty strong presence of saison still in the barrel. Also, with the pitched cultures already present in the barrel we felt that we may have been preferentially feeding a subset of the organisms active over the course of spontaneous fermentation rather than getting the expression of a more thorough set of microbes over the course of fermentation.

The barrel waiting to be filled the morning after the brew day.
To be clear the beer coming from the barrel was fine. It was pleasant to drink and I've used it in blends (here for example). But the beer was lacking complexity, and we were looking for something more from the investment of time and the potential that we knew the barrel had. Our slightly underwhelming experience is not to say that a solera system inherently won't produce the beer we were looking for. Though I do think perhaps it is better suited for certain styles, at least as it is practiced by homebrewers. And maybe our goals weren't aligned with the strengths of a solera-type system. The typical homebrew solera is a bit different from the traditional solera system (for example as used in sherry), where a multiple barrel system is employed. With this system, refilling is accomplished using the next oldest product when the oldest product is partially removed. This continues up the line such that progressively younger but already aged product does the refilling for most of the levels. On the homebrew side when it can frequently be wort or rather young beer and a one-vessel system, the refilling may not done with an aged product. That's certainly the way we did it at least. And our experience may have been better if we refilled with 6+ month old beer rather than <1 month old beer or wort.

About 25-50% of the pooled gear...
Anyway, this specific barrel wasn't on our ideal track, so we were looking to completely empty, clean, and re-fill either way. With that in mind, along with the selective feeding idea and the end goal of spontaneous fermentation, we decided to step away from the homebrew solera approach and opted for a complete fill from one brew day, open cooled at one spot overnight, and racked in to the barrel without pitching any cultures.

Planning the brew day
Completely filling a 225 L wine barrel on homebrew gear is not an easy task. We've done this before doing 3 brews in series. But that was with more simple infusion mashes and a shorter boil. With the long boils and intensive mashing process we were going for this time, we decided on brewing in parallel. If getting together with 3 of your friends to brew about 250-300 L of wort in order to have at least 225 L after overnight cooling sounds like a good idea to you, then I guess there's a few of us out there. If it sounds like a terrible idea, there's probably a good deal more in your camp. In all honesty it is probably a bit of both.

This much grain means a lot of stirring of thick mashes...
We started the planning with a list of the equipment we had available to make sure we had the physical capacity to hold and heat that much liquid. We were bringing together 4 brew systems using different methods of heating and mashing (electric BIAB, electric w/ false bottom, stovetop BIAB and propane w/ false bottom), which required some shuffling to make it all work out. But with this and with the additional miscellaneous gear we had, the brewday could go forward.

We split that gear into roughly 3 brews. Or at least 3 mashes, as some brews may require multiple boils. We designed these brews so they could be treated as more or less independent, but flexibility with this was key on brew day. In general things went as well as they did because we had enough people to problem solve and/or make runs for additional supplies as needed during the brew.

2 of the 3 propane boil kettles
By the end of April 2017, after weeks of planning and sending drafts with all of our equipment capacity and shifting vessels around to try to produce enough wort, we had everything sorted for the brew day:

-We planned for 3 mashes at the same time with one large electric kettle to heat the necessary strike and infusion water and one kettle for the combined turbid wort.
-The boil would be split into ~5 kettles, as needed. As the volume dropped during the boil, and as we cleaned larger pots from the mash, we could combine into 4 total.
-Our cooling plan was to use the bottom half of a Blichmann  conical fermenter and two of the boil kettles.

This gave us an estimated cooling capacity of around 285 L / 75 gal (we had to guess at the volume of the conical), which should be sufficient with evaporative and trub/hop losses to get near to the target of filling the barrel.

The two electric boils and the extra extractor fan.

The brew day
We used about 60% locally grown and malted barley and 40% soft white wheat. Our turbid mash had 4 rest steps (dough in, protein, cool saccharification and warm saccharification) plus a mash out and 2 turbid pulls. We generally followed the Cantillon turbid mashing process (see MTF and for more specifics here, see also Wild Brews by Jeff Sparrow and this Funk Factory writeup). The snags on the mash side were trying to evenly split sparge water across mashes of different sizes and different types of mashes (which inherently drain at different rates). This was compounded by stuck sparges on the largest of the mashes due to the high load of difficult grains.

While a benefit of turbid mashing is that it allows for overloading mash tuns, both in terms of fill level and in terms of proper conversion for good runoff, traditional Belgian mash tuns for this are more tuna can-shaped than our soup can-shaped tuns. So for the same volume our grain bed ends up comparatively deeper. This also made mixing difficult, as shown above, which could have resulted in worse conversion of the mash and could have contributed to the stuck sparge. Anyway, that was sorted out well enough, but it took a bit more time and made the splitting of sparge water (i.e. tying not to over-sparge some mashes and under-sparge others) trickier.

Cooling vessels 2 & 3.

Cooling vessel #1

We planned for a 3 hour boil and were fine with topping up the boil with water as needed. We wanted to fill the barrel completely so we were happy to take a small loss in OG if it meant a full barrel. We were hopping at a rate of around 3.8 g/l (based on the target end of boil volume) with aged pellets from hops direct and homegrown aged whole hops. We added these at the start of the boil. With the two electric systems going inside we needed to bring in an industrial extraction fan (in addition to the normal kitchen hood already active) to properly remove the moisture.

We left these beers to cool overnight. The nighttime low for the area on that night was just under 8 C (about 46F). Wort from the two electric boil kettles was transferred to the lower part of the conical fermenter, and therefore this wort was removed from the hops. The other two pots of wort were topped up with remaining electric wort and left to cool on their own, so these still had at least most of their hops in contact. The wort remained to cool for a total of about 16 hours before being transferred into the barrel and the wort temperatures on the morning after cooling were 12 and 14.5 C (53.5 and 58 F) in the two boil kettles. So the temperatures, both ambient and wort, worked out great.

Emptying the barrel.

Barrel cleaning
We had decided to empty the barrel on the same day as the brew day. We figured there would be enough down time during the ~3 hour boil to allow for this, and we didn't want to store the barrel dry or use any sort of storage solution if it could be avoided (as both of those would require extra work rinsing and/or swelling before we could use it). This did add the challenge of needing enough empty carboys to hold a full barrel, and transporting those as well as all the gear, but at least we didn't need any carboys for the wort going in.

We did this racking with a pressurized racking cane built with help from the engineer of the group. The basics of the cane follows this post on A Beer Diary, but with a cross instead of a plus to allow for a pressure relief valve (and this is a 1/2" cane rather than 3/8"). See also this FB thread on MTF. I'm behind on making use of the beer that came out, but that's another story.

With the boil done (clearing up some outside space) and the barrel empty, we could turn out attention to cleaning the barrel. We wanted to do a fairly thorough clean for a fresh start. Our strategy was primarily 2 parts - a prolonged spraying followed by steaming.

The barrel was sprayed out for a long time
We started the spraying with hot water at a laundry sink but we quickly realized our spraying goals were going to be better served by moving outside for the cleaning. The barrel was sprayed out with cool water until the water ran clear and tasted pretty neutral. This spraying also included some vigorous sloshing and rolling for good measure. This took a long time. I don't have notes on exactly how long, but all together it was 30 minutes+ of spraying, sloshing, dumping and re-spraying. Then the barrel was visually inspected and trouble areas were targeted until it all looked good. I spent much of this time becoming increasingly less dry...

Our spraying out also included wanting to spray the inside top of the barrel, but we weren't able to easily reach that. We were able to get around this by bending a standard racking cane (after first softening it with a heat gun) to about a 30° angle, or perhaps a bit smaller, and cutting the extra length of the cane off. This allowed the end to fit into the barrel and direct the spray back toward the top.

Now we had a visually clean barrel, but we had been using cold water which wouldn't do much to knock back the microbes that we didn't physically remove. For this we had a steaming plan. Steaming on a home scale can be a bit trickier. After trying to come up with some good way to do this, the engineer of the group came to the rescue with a converted pressure cooker. I think it is important to note here that you need to be very careful whenever you are working with steam and pressure. Be sure to have proper safety precautions in place and our method may not work for other setups/barrels. And there is definitely room for improvement.

We used a converted stovetop pressure cooker with the primary weight-based pressure relief valve removed to have a hose attached to this opening. This hose was then put into a bung in the barrel, transferring the steam from the pressure cooker to the barrel. We still had multiple levels of pressure relief. First off, the secondary pin to release pressure on the cooker was in and therefore there was pressure relief on the cooker side. Secondly, we had multiple press-fit connections leading to the barrel to serve as release points in case we built up too much pressure. These were the connections from the tube into the bung as well as the bung in the barrel, which was not forced down as tight as one might do when aging in the barrel. We knew from experience with the racking cane that the bung could pop out under a low pressure when it is not strongly forced into the barrel.

Steaming the barrel.
We started the steaming of the barrel with our "Vinnie nail" out, allowing venting of the steam out of this opening. With this, while steam entered the barrel, the barrel was not warming up as much as we would have liked. So we replaced the nail after about 5-10 minutes and continued steaming in a closed system with the aforementioned engineered weak points (or if German-inclined, sollbruchstelle - one of my favorite German words). I didn't keep good track of steaming time, but it was clear the steaming was doing its job. First the heads of the barrel became warm to the touch. The exterior of the barrel was wet from rinsing before the steaming, and we could see this moisture evaporating away. Then the sides of the barrel also became warm to the touch. Eventually our engineered weak points did their job, venting the pressure, and we decided to end the steaming there. We felt a sufficient enough job had been done as it was probably at least 20-30 min of total steaming (with and without the nail in place) and all exterior surfaces of the barrel were quite warm.

With a bit more planning time we'll hopefully have a better setup next time. I think it wouldn't be too tricky to work in a pressure relief valve like. Basically the same design as the racking cane should work (and only a T fitting would be necessary, rather than the cross on the cane). Though again, from out experience, the bung on that cane pops out before the pressure relief valve is active anyway. But more pressure relief options are probably not a bad thing. Another option would have been to try longer with the sampling nail out. Perhaps with more time to build up heat this would have worked well.

We returned the morning after our brew day to fill the barrel. The pots that could be lifted easily were carried over to the barrel for filling. The others were transferred into intermediate smaller pots and then carried over. Filling the barrel went fairly smoothly, but it was clear fairly after working through the conical that we had undershot our volume. We had a bit more than expecting in our evaporative loss. And a calculation error meant that we were high in gravity but low in volume. This was an easy problem to solve and we diluted in the barrel with extra water (which had been heated to above pasteurization temps from the day before). In the end, based on a gravity points and volume calculation, we had an OG of around 1.055.

Other than this volume challenge, and some slow flow on one of the kettles due to clogging a hop filter, the filling of the barrel went pretty smoothly. We ended up leaving a small amount of head space in the barrel. It probably only amounted to about 10-15 L, but we figured this might help keep the avoid absurd blowoff while still keeping the barrel almost completely full. And we filled a carboy with the extra wort for fully topping up the barrel after primary.

Fresh greens and cleaning, an important part
of every brewday. photo: J Young.
Interestingly, there was a clear difference in the fermentation progression of the barrel and the carboy. This fits with data on the inoculation of lambic from Spitaels et al. (2014), which reported microbes present inside of cleaned barrels that weren't detected elsewhere in the brewery. It is certainly possible to clean a barrel more thoroughly than we did, but I think we did a pretty reasonable job with the physical removal and then given how warm the outside of the barrel was after steaming.

For me, this difference in fermentation from the two vessels helped to confirm previous anecdotal experience form myself and other as well as available published data that fermentation vessels can impact inoculation in spontaneous beer. I am not very convinced that a barrel can be made sterile / as clean as a carboy and I think this can be important. Anyway, after a few months (from reports from the other folks involved in this brew) the carboy was a bit unpleasantly bitter while the barrel did not have this bitterness. The carboy was transferred into the barrel after we felt that the risk for blowoff was gone. The barrel also developed a bit of a "sickness" after active primary fermentation while the carboy did not.

I'm excited to see how this beer develops over the coming year(s). Hopefully I'm back around to deal with it when we remove it. And hopefully I can be involved in the next ill-advised filling session. Our plan for now is to let the beer go in the barrel for a couple years, while monitoring it's progress here and there. We're certainly not in a rush to empty it and re-fill it.

Monday, August 21, 2017

A quick autobiographical update

I wanted to give a quick update on what I'll be up to in the coming months (to years) and how that will influence the trajectory of this blog. While there isn't really much beer content in here, this is a bit long for a FB post so I thought it should stand as an autobiographical blog post of sorts.

Picking sour cherries in Bern, summer 2017.
Starting in October I'll be moving to Bern, Switzerland to take a 2 year position as a post doctoral researcher. In may ways this will help me maintain the trajectory of the blog over the past few years (in itself, this has been caused by similar life circumstances). I've made at least one trans-Atlantic move every year since 2013, and these trips have become more frequent and for a shorter duration in recent years. So I'm hoping this time there is a bit more stability.

For the blog, I think while I expect to be brewing much less, I think the writing will mostly stay the course. While having a base in continental Europe means leaving brewing gear behind, it should help me maintain access to the sorts of historical sources and modern brewers that have featured in many of my posts over the last few years. So I expect I'll be more likely to write the sort of posts that have been up recently - a focus on historical sources and scientific articles, and possibly a return to posts about commercial producers, rather than my own brewing. I am hopeful that I can get a bit of brewing in though.

While Switzerland may not be known abroad for it's beer, I think Bern is a good spot to end up. I've already met a homebrewer there (Tom) who is making good beer. Some of it is available commercially with his brewery Full Measure Brewing. While vising Bern I was able to pick some sour cherries with him and learn a bit about the Swiss beer scene. The area is also home to Sam, the writer of the (no longer active) Eureka Brewing blog and the co-owner of Blackwell Brewery. So there should be some good beer options around Bern.

Speaking at Carnivale Brettanomyces 2017.
Being based in continental Europe will also hopefully allow me to integrate a bit better into the European brewing scene. So far most of my time around European brewing has been getting to know commercial brewers. I definitely plan to continue that, but I'd like to spend a bit more time with homebrewers there. There is some great stuff going on in European homebrewing/blending (and very small scale commercial brewing).

While these brewers are often operating with similar influences to what drives North American homebrewing, and while there are points for the two realms to interact such as Milk the Funk, I think the two sides could benefit from a bit more crossover. But major events (like HomebrewCon and Carnivale Brettanomyces) can already have a non-trivial cost when considering places to stay, etc. It doesn't get better when you add international flights to the bill. And the almost overlapping schedules of these two don't make it any better. But it would be great to see more crossover at these events. So I'm hoping that I'll be able to learn from and collaborate a bit more with European homebrewers while I'm in Switzerland. Feel free to get in touch if you're a homebrewer based in Europe and hopefully we'll be able to meet up at some point over the next couple years.

Monday, July 24, 2017

White Beers of Northern France

About a year ago I posted a brief bit of information about bières blanche from northern France on the blog's facebook page (here and here). Thanks to a friend in Brussels with a good library of historic texts, I was able to locate a bit more information about these beers. This post expands on those initial FB posts with the additional info that I've tracked down. But there is still a long way to go to understand these beers, and I'll continue to look for more sources.

The Nord region of Northern France was an active brewing center around 1900. At this time, breweries in the region were still producing traditional beers of top fermentation. The influence of imported lagers was shifting brewing elsewhere in the country toward lager production. Unfortunately, while traditional beers could still be found in the Lille and Dunkirk areas, they were also in a period of decline here. With WWI coming and the state of brewing in the region already in a tricky spot, the region saw large changes for brewing in a rather short amount of time. I've written about biere of the region in these two posts here (mainly on mashing) and here (mainly on WWI).

Perhaps not a brewery making a blanche, but I wanted a photo generally related
to historic French brewing. From the breweriana collection of D. Thiriez.
So back to the beers of the Nord. Most of us have probably heard of one of these traditional beers - bière de garde (note that bière de garde in 1900 was different from the modern versions) - but other beers were made in the region as well. And I haven't seen much mention of these other beers. While looking for information about French bière de garde about a year ago, I found mention of a bière blanche. I hadn't heard of this beer before and it interested me, but there was very little info to go on in that brief mention. With this new source I'm starting to get a bit of a better picture about this beer and wanted to put up what I know at this point.

Of course, as with other posts on historic brewing, the same caveats apply - namely that this is a small snapshot of the beer (as the beer likely changed over time as well as among different producers) and this understanding is limited to the info given in a few sources.

Blanche de Cambrai
This discussion draws from two main sources - Petit Journal du Brasseur (1910) and Moreau and Levy (1905). The both refer to blanche in general and the latter specifies a beer called Blanche de Cambrai. In the modern world, this latter name applies to a distinct beer made from one brewery. But historically it was a style of beer brewed by many brewers in the region. The same thing - where a style turns into the product of only one brewery - can be seen elsewhere in Europe (e.g. Grisette and Hoegaarden). I'm not sure if the brewery making Blanche de Cambrai holds a trademark on the name, as is the case with the other two examples. When discussing Blanche de Cambrai for the rest of this post, I am referring to the historic style rather than the modern brand name.

Historic Blanche de Cambrai mostly matches the general description of blanche in PJB, but there is a notable difference in attenuation. On the whole, these white beers don't seem very common but they were produced at multiple breweries in the early 1900s. They are noted as having a short boil or possibly none at all (though in the latter case beer would be held at boiling temps, so maybe more of a simmer than no boil in the modern sense). For the time this is quite unusual as beers could easily have a multi-hour boil, possibly approaching 8-12 hours or more.

The blanche beers seem to be of moderate gravity (~1.035-1.040) and were lightly acidic. Some of the parameters of the beers are shown below, along with comparison to other blanche beers and acidic beers, both modern and from ~1900. These northern French white beers are described as having a good hop aroma. The attenuation was either moderate or high. It seems the beers were consumed around 3-4 weeks from brew day (or possibly a week or two older).

Parameters of northern French Blanche and historic and modern Belgian and German acidic beers.
The grain used is described as being as pale as possible. Moreau and Levy note that an ordinary brown beer was brewed at the same time and from the same grist as this white beer (this brown beer is not completely straightforward, but that is a topic for a later post). Unlike bière de garde, which would use a form of turbid mashing, it seems that the white beer is produced by infusion mashing. About 25-30 kg of grain is used for 100 L. I interpret this to mean 100 L of each blanche and brown beer (it isn't explicitly clear, but given context and expected extract this seems necessary). There is no discussion of grain breakdown (and actually no mention of wheat by name in either source). The barley used in this region was mostly a winter 6 row. There is also general mention of brewers in the region using a bit of straw to help with the lautering, which agrees with other beers brewed with wheat at the time in Belgium such as lambic and grisette (as discussed here). Moreau and Levy note that some brewers use rice.

Initially a cool infusion is made and the mash is quickly drained. This is effectively a rinsing, and is done to remove some of the color of the grain. This rinse is held to the side and will be added the the brown beer. Then the mash is raised to a low saccharification temp, where a long rest is performed (~1 hour of stirring followed by 75 min of rest). After this the mash is drained and first runnings become the white beer. Note however that the white beer is not especially strong. The remaining runnings (and the cool rinse) going to the brown beer.

The white beer portion is boiled for up to about an hour (though Moreau and Levy note that some brewers only hold the wort near a boiling point, in agreement with PJB). Hops are only added in the cooling tuns or at the end of boiling (preferably in the cooling tun), but the hopping rate is fairly high at ~9-10 g/L (compare with grisette and saison/Belgian bières de garde here and with lambic here). Moreau and Levy note that some brewers spiced their beers with coriander, star anise or iris.

The beers are fermented with ale yeast (which, given the time means a mixed culture of bacteria and/or other yeasts such as Brettanomyces). Although the hopping was high, the hops were not boiled and some acidity is able to develop. The beer was bottled (with priming sugar) after a couple weeks and was carbonated a couple days later.

Final Thoughts
All this seems like an interesting beer - light acidity, low gravity (in the modern sense) and hop flavor but not so much bitterness. It sounds like it would be pretty refreshing. The brewing process described in Moreau and Levy seems pretty unique and I wonder if other brewers in the region followed a different process for their beers. And/or if similar process shows up for other beers elsewhere. Overall I think this is a cool, if uncommon, component of northern French beers from ~1900. And hopefully I can find some more info elsewhere about these beers.

Sources for the text:
Petit Journal du Brasseur, 1910
Traité Complet de la Fabrication des Bières (1905), Moreau & Levy.