Saturday, December 27, 2014

Soma at Moon Under Water Brewpub

It is probably the dream of most homebrewers to get to brew a big batch of one of their beers on a commercial system. In October Moon Under Water, one of the local Victoria breweries, asked me to do just that - brew a 10 HL (8.5 barrel) batch of my favorite recipe: Soma, my saison. I was honored to get this offer and both excited and nervous to try it out. This is a recipe I've worked pretty hard on over the last two years. Working on the yeast blending for saisons (post 1 and post 2), tuning the mild acidity levels from pre-primary souring, and in general trying to work out the hop balance. I feel like I have it somewhat close to where I want it on a homebrew level (although the recipe is always evolving) but trying to scale up the recipe definitely presented new challenges. This write up details the brew process, what I learned from scaling up my recipe and brewing it on commercial equipment, and what I would like to do differently next time.

Just hitting a boil.
I have to say from the start here that Clay and Jeff at Moon Under Water were great to work with. They were open to whatever I wanted and gave me complete control over the recipe and process we'd take. And any decisions heading into the brew day regarding making this beer that deviated from my homebrew recipe were my own and were made considering the different equipment, process, and risks involved in a commercial batch. With some of the batches leading up to this brew I had been pushing the acidity of the beer. With some of these brews possibly slightly too acidic, or at least a bit out of balance, I backed down on the target acidity a bit. I also backed down on the hopping load. This was due to both my expectations of increased utilization on a commercial system and my experiences with some rough hop character recently in some homebrew batches (earlier batch of Belgian single and Sour-Worted Soma).

There are definitely some challenges when scaling a recipe up to a commercial size, as commercial brewers and any homebrewers that have done this or looked into it know. I'm really happy with how our hot side went, and I don't think we ran into much trouble there, but the fermentation definitely presented some challenges. These snags sort of acted together as one, with one feeding into the other.

We went with the yeast blend that I normally use, and I think this is really important in producing the character of the beer. I had never grown up the sort of yeast we were going to need for this batch, so I dropped off a pack of each of yeast for the brewers to grow. Generally they either use dry yeast or talk to local brewers for a pitch (the breweries here seem to cooperate well and share yeast/knowledge/etc. freely with each other) when they want to use a new yeast. So it turned out that we both didn't have a ton of experience growing up yeast from packs to ~1000 L pitches. So we didn't quite grow enough yeast and the first challenge we faced is that we pitched at a lower rate than I generally do. This lower pitch rate, and the subsequent slow start to fermentation, fed into the second and main challenge we faced.

Filling the open fermenter.
We fermented this beer in an open fermenter in Moon's 8-vessel fermentation room. As a side note, adding the yeast was a bit of an adventure. We had the yeast in carboys and we added it by swirling up the carboys and carefully pouring it in over the top of the open fermenter. The top of the open fermenter is about at my chin, which made pouring full carboys a bit tricky.

Many of the other fermenters of the fermentation room were sitting at cold-crashing temps, and because the room is rather small and can be isolated from the rest of the brewery by a set of double doors, the fermentation room  was rather cold. Because we used an open fermenter our fermenting beer was not as insulated from this cold room as a normal cylidroconical would have been. So although we didn't have the glycol jackets on, the cold room definitely had an influence on the beer.

We were working with a notoriously tricky yeast (Wyeast 3724, Belgian saison) which is especially temperature sensitive. Starting with a low pitch rate meant that we got off to a slower start and didn't generate heat from fermentation as quickly. This insufficient generation of heat then fed back into lower beer temperature and lower yeast activity, which cycled back into continued insufficient generation of heat. So because out pitch rate was low, the fermenter was sitting in a cold room, and we had no way to warm our fermenting beer (although I knew this was going to differ from my home brew process going in the big batch, the impact of this limitation was greater than I expected it to be) our fermentation never got warm enough. And this significantly suppressed the 3724 character and left more work for the small helper pitch of 3711 to take care of.

The fermenting wort.
This was evident from early on in the fermentation, and it left it's mark on the final beer. So now the point has been driven home that if I use 3724 on a commercial system, I will need to set things up better to keep a fermentation warm, and possibly come up with a way to add a bit of extra heat. I do have the ability (sort of) to see how this batch would have been had the fermentation gone according to plan. We filled one 6 gallon (23 L) carboy which we temp controlled the way I normally would to compare how the commercial sized fermentation (temperature, hydrostatic pressure, etc.) changed the beer. Although I haven't done a side by side tasting yet (the beer from the carboy is still bottle conditioning), at bottling I did prefer the carboy version to the open fermenter beer.

Racking into the barrels.
After 4 days in the open fermenter we transferred the beer to a 10 HL horizontal tank and 2*225L wine barrels. The jackets were turned off on the horizontal tank and the beer was allowed to rise as far as it would (which wasn't much due to the sluggish fermentation) until it reached terminal gravity. The gravity was still pretty high after about 2 weeks (it was at about 1.015) so we decided to prepare a pitch of S. trios (White Labs WLP644 Brett trois was recently determined to be a Saccharomyces yeast rather than a Brettanomyces strain, and I will refer to it as S. trois from now on). We decided to give the beer a couple more days to see if it would finish up on it's own, but after about 2.5 weeks the beer was only down to 1.010 and I was tasting something that I often, but not always, get out of the French saison yeast (Wyeast 3711) that I would prefer to not have. It is sort of a green and yeasty character, a friend of mine recently described it as being a bit like green bananas. So we added the S. trois and gave it a couple more weeks to finish up and clear.

The two wine barrels came from Averill Creek and formerly held red wine followed by blackberry port. This was their first use for beer, but they had been filled with water at the Moon. The barrels were inoculated with a base of Yeast Bay Amalgamation blend (thanks to Jeffery for giving me a good pitch of this) and Wyeast 5223 Lactobacillus brevis. In addition one of the barrels has some ECY02 Flemish ale blend from East Coast Yeast, an excellent source for unique yeasts and funky blends, and the other barrel had an addition of S. trois. They are aging nicely and I am really excited for how they turn out. At this point the ECY barrel stands out a bit with some mild but developing funk but both barrels have a nice complex fruityness from the saison yeasts and Amalgamation blend. The acidity is starting to show up and they can age a while longer without being in danger of pulling too much oak/barrel flavor. We'll see how they change over the next month and maybe there will be some additional cultures added if needed, but I am definitely happy with how they are now. I expect that they will be blended together at bottling.

I marked the barrels with some inspiration from Brussels
Brew date: 20-October-2014
Batch size: ~1100 L (9.4 bbl)
OG: 1.049
FG: 1.003 (1.000 on the 23 L carboy)
Target IBU: ~25 (some guesswork here as I don't know the utilization of the big system and the process changes that go along with it).

87 % Best pilsner malt
7.5 % Best Vienna Malt
5.5 % Weyermann Acidulated Malt

Saaz: 800g with 30 minutes left in the boil and 1430 g grams added at whirlpool
Hallertau: 1100g with 30 minutes left in the boil and 1430 g added at whirlpool
Wyeast 3724 Belgian Saison, ~80% of the total yeast pitch
Wyeast 3711 French Saison, ~20% of the total yeast pitch
WLP 644 S trois added to the clean portion after ~2.5 weeks.

Both barrels were inoculated with Wyeast 5223 Lactobacillus brevis and Yeast Bay Amalgamation blend. One barrel also got a bit of ECY02 Flemish red blend and the other got S. trois.

Breakbright was added following what they normally do (I don't know the exact amounts).
CaSO4 and CaCl2 were added to boost Ca 92 ppm, SO4 167 ppm and Cl- 39 ppm in 10 HL. Victoria's water is pretty low in everything so these are reasonably close to the final concentrations.

In addition to the saison in barrels I have started helping out the brewers at the Moon with another barrel project. And in addition to these two barrel aged projects there will likely be some more clean and funky beers to come out of collaborations with the brewers at the Moon. I'll keep the blog and facebook page updated with these projects.

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