Thursday, October 30, 2014

Sour-worted Soma tasting

I've been experimenting a bit with ways to add mild acidity to certain beer styles before beginning primary fermentation. For this recipe I fermented a portion of a previous beer with a similar grist with Lactobacillus until I was happy with its acidity and then blended that portion back into the boil for this brew day.

Aroma: Peachy and citrus, the tartness is there, tangerine, strong Wyeast 3724 floral aroma. There is more Wyeast 3724 character in the balance than I feel I usually get from the yeast blending. There is a pleasant mild minerally character and a mild funkyness/rustic aroma (enough that one might wonder if there is brett in here).

Appearance: Thick fine very large white head (I gave a bit of an aggressive pour) with excellent head retention. The beer is a finely hazy straw color. It is pretty and hits what I am looking for appearance-wise in a saison.

Taste: There is a nice dry citrus fruityness (tangerine and mild lemon) and floral yeast character. The yeast character is strong and pleasant with some peach in there with the citrus. The hops come through a bit muddled, which is influenced by a rough planty hop character in the finish. I'm not sure if that is due to hop material making it into the fermenter and sitting warm with the beer for an extended period of time or related to the lower boil pH with the hops (or both, and more on this below). But it is definitely something I'll need to work on for future batches. The yeast fruityness becomes more prominent in the balance with warmth and the hop flavor becomes lower in the balance with warmth. The acidity is a bit higher than I'd like it to be for this beer. There is a nice hop bitterness before the roughness comes in.

Mouthfeel: The beer has a pleasantly prickly high fine carbonation. The body is light with a nice smoothness and the lightly tart finish is great. There is a bit of warming in the finish (probably due to both the acidity and the alcohol). That planty character in the finish is noticeable in the mouthfeel as well as the flavor.

Overall Impression: This beer is good but not where I wanted it to be. For a first order try with this method I think I got some good information out of it and I like the way the acidity is working with the yeast character. There is a hint of flavor I've gotten from stressed 3724 before, so the low pH might have stressed out the yeast a bit (or maybe it was something else). Either way it is really low level and I don't mind it. I would probably bring the acidity down a bit on future batches anyway. I don't think the low fermentation pH had many effects on the yeast and I think if I lower the acidity a bit, as I wanted to do independent of it's influence on yeast character, I think the pH wouldn't be a problem for the yeast character. And that seems to be going away with more conditioning time. Overall the beer is also improving with more conditioning time.

The aroma is great and overall the flavor is good. The acidity brightens the beer and lightens the body. The flavor is great when I get past the roughness of the hops in the finish. That is something that I am especially sensitive to in my beers and I think many people would miss it if I didn't mention it. I sent this off to a competition, where it scored better than I expected, and one of the judges said something briefly about some astringency, but didn't talk about rough hop flavor or anything like that.

I think the big thing to work on with this batch for me is the rough hoppyness. I've gotten that recently with another beer without any pre-primary souring and with a comparable hopping regiment, which leads me to believe it is primarily driven by what is happening with the hops and not the pH of the boil. I've had similar hop amounts at similar timings to this batch without any problem, and have also noticed with previous batches that if I get too much hop material carryover into the fermenter than I am prone to getting this flavor, so I think that may e the big issue.

The roughness is in the lingering aftertaste after the finish and if I'm not thinking about it I can not notice it. And then I think the beer is great. After this batch I switched to hop bags to try to limit hop material getting into the fermenter (partially driven by switching boil kettles) and I haven't run across the hop roughness anymore. Some batches have worked great, like the re-brews of my Belgian single and petite saison, but I also have had batches coming out less hoppy than I'd like, leaving something missing. I'm not totally happy with the hop bags and am still looking for a better solution to keep hops out of the fermenter while getting the hop character I want.

So overall the beer is good but not up to my standards. But I don't think much (or possibly any) of that has to do with the method of getting acidity. The 1st attempt at sour-worting was a reasonable success even if the overall beer didn't hit the target.

Wednesday, October 22, 2014

Yeast Blending continued- A worked example with Petite Saison

To follow up the introduction for how I go about yeast growing and blending, I wanted to give a worked example of how I handled blending in a more advanced scenario. It could certainly get much more complicated than this, but I think this is a good way to show my process and the potential value that yeast blending can add to brewing. As a warning, this is on the more technical/math side of things and this approach may not be what you're interested in. It's pretty dense but if you are really interested in blending yeast, and you want to do it in a controllable way, continue on. I try to break down the steps simply and repetitively so if you get it right away, excellent and sorry for the redundancy. And if you feel like you are missing something let me know. I probably wasn't clear enough and I though about this for a LONG time before actually doing the blending, so it took me a while to understand it. And it took me a while to work out the best way to do it. I think if you want to do yeast blending in a repeatable fashion you are going to want to think about blend ratios and total pitching rates. So here's how I do it in a more tricky situation...

The setup: I have been using a blend of Wyeast 3724 (Belgian Saison) and Wyeast 3711 (French Saison) for almost 2 years now and have been really happy with the results. I get a majority of the flavor profile from the 3724 combined with the reliable and excellent fermentation behavior of the 3711 and a nice complexity from additional flavor. So far this blend had been based on wanting that flavor balance with 3724 dominating, but I hadn't run any trials to find an optimal blend. So batch to batch blend ratios would swing from about 60%/40% Wyeast 3724/3711 to 90%/10% Wyeast 3724/3711 based on what I had available at the time and what splits worked best with the cell count splits I had of the individual yeasts. It was time to run some controlled yeast blend ratio trials to work out what the optimal blend is for what I want my saisons to be.

The yeasts used in this blending
I was also starting to run low on petite saison and I was really happy with how that recipe worked out in my first batch. With summer fading away I thought I would try to get a re-brew in and use that recipe, a beer one can drink larger volumes of and that is on the simple side for recipe, as a base for working on these yeast blends. The goal, as I break down in my Petite Saison Rebrew post, was to target a blend on the upper end and on the lower end of the range that I usually fall into for my yeast blending. In addition I made a blend with a third yeast, Yeast Bay Wallonian Farmhouse, and in a fourth carboy I used the 3724/3711 blend on the upper end of the range I usually fall into with additions of Brettanomyces and Lactobacillus.

The Blending: Before I started any of the blending I got out the yeast I had and thought about the cell counts I had in each container. In the petite re-brew post I refer to 80/20and 60/40 blends, and I have also referred to these in the bottles I gave away. In my brewing notebook I refer to 85/15 and 70/30 blends, which were my actual target going into this. The 80/20 and 60/40 must have come out of what I thought I had done after the fact (as it turns out that was not the case).

Anyway, I made a table with my target blend ratios and the total number of cells I would need in each carboy based on the Mr. Malty calculator. I had jars of ~110 billion and ~150 billion cells of Wyeast 3724 and of ~65 billion cells of Wyeast 3711. Conveniently for the main two carboys the total desired pitch worked out to 100 billion cells each based on my OG and volume. I also knew full and empty weights of my jars (I approximated the empty with another jar of the same style/size). I blended the 150 billion cells of 3724 and the 65 billion cells of 3711, making a blend of roughly 70/30 with ~215 billion total cells.

My Target Blends

Knowing the full weight of this jar and an approximated empty weight, I knew the weight of my blend slurry which was ~215 billion total cells (150 of 3724 and 60 of 3711). For a pitch of ~100 billion cells of my 70/30 blend I needed to add a bit under half of this slurry. After adding the appropriate pitch of this slurry I would have about 115 billion cells left in the 70/30 blend (210 to start - 100 needed, approximately 80 billion cells of 3724 and 35 billion of 3711 left).

To this I added the extra 110 billion cells of 3724 from the other jar, making an approximate total cell count of 225 billion cells composed of ~190 billion of 3724 and ~35 billion of 3711, a blend ratio of roughly 85/15. Knowing the new full mass of this blend and the same approximated empty jar mass I could add a bit less than half of what I had to add ~100 billion cells to the target 85/15 blend, leaving me with ~125 billion cells in 85/15 target blend left over.

Okay, so I've added the yeast to my first two carboys and it all worked out pretty smoothly. Now I have 2 carboys remaining: 85/15 blend plus brett and lact and the carboy with Yeast Bay Wallonian Farmhouse (which I'll call WF from here on out). For the WF blend I have a blend ratio of 62% 3724, 27% Wallonian Farmhouse and 11% 3711 in my notebook. I honestly don't remember my reasoning for such a precise and strange ratio. I had no reason to choose a specific amount of Yeast Bay yeast to add, except that I was happy with the character from using it in my Barrel Aged Saison. So the choice probably came from how many cells I needed and how much 3724 and 3711 I had left over. If I actually worked it out that exactly I must have been pretty sharp at that point in the process.

I had ~125 billion cells left and based on volumes and OG I would need ~85 billion cells total in the +brett and lacto (+BL) treatment and ~55 billion cells total in the WF treatment. I couldn't meet my desired pitch counts with the 3724 and 3711 I had left, but that's good because I would be adding other yeast/bacteria. I would slightly underpitch Saccharomyces to the +BL carboy and make up for this with brett and lacto to come to my target, while potentially overpitching total cells a bit. And I would underpitch 3724/3711 and add Wallonian Farmhouse to hit my target of 55 billion cells in the WF treatment. Back calculating based on those targets I wanted to add approximately 75% (~82 billion cells) of 125 billion remaining 85/15 blend to the +BL treatment, leaving ~43 billion cells of 3724 and 3711 for the WF treatment. Since that is a pretty even split, it must have determined the strangely specific 3724/3711/Wallonian Farmhouse ratio from above for the WF treatment.

I find it easier to think about the blending from this perspective after the fact and I would suggest carrying on like this, but during my actual blending I did the last 3 blends in the the opposite order (adding ~125 billion cells of the target 85/15 blend to a combination of WF and +BL treatments and leaving the rest for the normal 85/15 target blend).

I kept the Wallonian Farmhouse yeast separate, since it was only going into one carboy, to make up the difference in case I messed up on one of my pours. The same can be said for the brett and lacto. I didn't add known numbers of cells of those, but I could add more or less based on how much Saccharomyces I added. So with this target plan all thought through, I went ahead and did the blending. My actual blend ratios are shown in the table below. As it turns out, my Saccharomyces blends were 86/14 (Wyeast 3724/Wyeast 3711), 70/30 (Wyeast 3724/Wyeast 3711), and 69/12/19 (Wyeast 3724/ Wyeast 3711/Wallonian Farmhouse). So a pretty good job hitting my targets overall.

My actual blends. Wallonian abbreviated Wall. Cells added from (slurry mass added) / (total slurry mass). Cells of each type added from (total cells) * (% of each type) /100. Total cells remaining determined from (initial counts) - (added).
I think this was as successful as it turned out to be was due to the meticulous planning of target blend ratios and how I would come up with those based on the yeast I had. Keeping target pitches simple fractions of my total blend volumes (in two of the four cases it was about 1/2 of my blend and in the remaining two it was 75% and 25%) made this simpler to execute. And if my jars of yeast did not break down so easily into these blend ratios I would have either adjusted my target (with this blend ratio trial, targets were pretty flexible as long as I had one as a high % of 3724 and one as a lower %) or I would not have added a full jar. Keeping things as fool-proof as possible when it comes to pouring into a carboy is key here.

Hopefully this approach made sense. Definitely ask if you're stuck on something. And hope it proves helpful to you if you decide to try your own yeast blending. It definitely doesn't have to be as complicated as this so don't feel scared away from doing your own blending if this seemed too much. It's something I had to work up to from doing a bit of more simple blending first but I think it is a valuable approach to optimize your blending and to controllably try out different yeasts.

Thursday, October 9, 2014

Petit Saison Rebrew

The grist
I was really happy with my first batch of petite saison, and though I knew by the time the re-brew was ready it wouldn't quite be summer anymore, I figured it would be ok and the beer was definitely worth re-brewing. Since it is a pretty straightforward beer recipe wise, it was also a good candidate for refining my yeast blending. Previously my rough target of ~80% Wyeast 3724 Belgian Saison, ~20% Wyeast 3711 French Saison wasn't really based off much in terms of specific test results. I wanted the flavor profile of 3724 to be prominent over the profile of 3711, it was a convenient blend for some earlier batches, and I liked the results of those earlier batches. So it was about time to test that blend ratio out. In order to end up with a good amount of 3 or 4 different blends, I opted for a 16 gallon batch. That also gave me a good opportunity to test out some newer equipment on a pretty low-stress brew before I really needed to count on the equipment and know it's quirks.

A full 20 gallon pot during the boil
The brew day went pretty well. Because my OG was so low I was especially wary of over-sparging. I held some of my sparge water to add straight to the kettle rather than using it as sparge water in the mash tun and I was prepared to top up more as needed. The wort was split into 4 carboys. 3 were kept 'clean' (with only Saccharomyces) and one carboy got Lactobacillus and Brettanomyces in addition to normal yeast. As I mentioned above, one of my big goals with this beer was to try different blend ratios to see what I should set as my target blend for future batches of saison.

For the blending I chose my usual target for the blend of saison yeasts I normally use (~80% 3724, ~20% 3711), a blend more heavy on the 3711 (60% 3724, 40% 3711) and a blend incorporating a third yeast (60% 3724, 20% 3711, 20% Yeast Bay Wallonian Farmhouse). Usually my saisons come out with a blend somewhere between the first two based on convenience, so the goal there was to determine how much that blend ratio really matters. With the third option I wanted to see if I could improve the blend by adding a third yeast. And I was happy with Wallonian Farmhouse and had some around from my barrel aged saison (which just came out of the barrel and is tasting pretty good), so that became the third yeast to put into the blend. Keep in mind that those percentages were targets, and while I was roughly close to that (I recorded what I actually did), the exact numbers are a bit different. It might be worthwhile putting up how I did that blend as a more advanced follow up to my intro to yeast blending. So I'll save a detailed work up of the blend ratio for there.
The Saccharomyces strains for this batch
Batch Size (vol in primary): 16 Gallons
OG: 1.031
FG: 1.001
IBU: ~21 (Tinseth)

36.1% Doehnel Pale Munich (6-7L)
35.8% Doehnel Light Pils (1.5L)
13.5% Wheat Malt
8.5% Weyermann Acidulated Malt
6.0% Caravienne

Adding the caravienne was a change from the first recipe, and we'll see if I like the addition or not. Generally I avoid that sort of malt in pale saisons. However given the especially low gravity of this one I thought maybe it would help boost the malt perception (even though the first batch did come out with a pretty good malt character).

84g Hallertau Mittelfrueh pellets, 4.5% aa
77g Tettnang Pellets, 4.3% aa
20g Slovenian Bobek pellets, 5.09% aa

Wyeast 3724 Belgian Saison
Wyeast 3711 French Saison
Yeast Bay Wallonian Farmhouse

And in the 4th carboy:
Yeast Bay Lochristi Brett blend
Wyeast 5223 Lactobacillus brevis

CaSO4 and CaCl2: +95 ppm Ca2+, +113 ppm SO42-, +71 ppm Cl-
Victoria's water has very low levels of dissolved ions so these addition levels are basically the final concentration.
1 Tab Whirlfloc
1 tsp Wyeast yeast nutrients

4 carboys fermenting (uncovered for the picture only)
85 minutes qt 150 F (65.6 C), roughly half of the acidulated was added with the rest of the grist and the other 1/2 was added with 15 minutes left in the mash. No mash out above 160 F (71.1 C) to continue conversion into the kettle.

Boil plan:
90 minute boil. I topped up with water as necessary to hit my targets. I didn't want to over-sparge so I expected I would need to top up a fair bit. I used hop bags for this brew as I was using a new larger boil kettle and I didn't have a good way to keep hops out of my fermentation otherwise.

1st wort hops: 12g Tettnang and 19g Hallertau
25 minutes left in boil: 20g Slovenian Bobek
20 minute steep after flame out: 65g Tettnang and 65g Hallertau

Fermentation Plan:
Pitch at 60-70 F (20-21.1 C) and let it rise/warm it up to 78-80 F (25.6-26.7 C) over the first 3 days or so.

3-Aug-14 Brew Day

13-Aug-14 Turned my aquarium heaters off in the fermentation baths and let the beer temp drop to room temp over the next day and a half or so.

7-Sept-14 Bottled. I went away for two and a half weeks at the end of August/beginning of September so I wasn't able to bottle any sooner. But spending that much time in the primary fermenter was not a problem.

Here are the tasting notes from this batch.
The three 'clean' blends (+1 other batch) bottled