Brett Cake Removal and Reuse

[cactusgarrett]

Hopefully this will be a simple question for people much smarter than myself. I did a 100% brett L. beer a few days ago, which is chugging along just fine, and my question is related to taking the beer off the primary cake after a couple months:

I'd like to get another batch of something different going next, and I plan on one of the pitches (after primary fermentation) for that to be the same brett L. i used for this 100% brett L. batch (WY5526). If I pull this 100% batch (~1.080 OG) off of its cake to harvest it, say, 2 months into fermentation, will I be doing any noticeable harm, assuming it's close to expected FG? I've read that 100% brett ferments (at least with lambicus) could take a few months to come into their own, but I'd really like to use this slurry instead of purchasing another pack (which may or may not be available).

 

[dantheman13]

Yeah, racking off of the cake is fine. There is plenty of yeast in suspension, especially when it comes to Brettanomyces.

 

[Yeroc]

If it's 100% brett, treat it like you would a normal fermentation with a saccharomyces beer yeast. From my understanding, and limited experience, 100% brett fermentation doesn't take months to drop to a final gravity in the same way it does when brett is added with another yeast. Your fermentation should move along at a fairly quick rate and not take months.

Of course the size of your yeast pitch is a factor in how quickly fermentation is complete (as well as fermentation temp, etc). Plus at 1.080 OG it might take a bit longer than something with a lower OG, but I think we are talking weeks, not months. I would say you're okay to rack off the yeast cake in 3 or 4 weeks although your hydrometer should be your guide. The only issue I see with reusing the yeast cake is that this first beer will have a pretty high ABV which can stress yeast - at least a normal beer yeast. Maybe someone else knows if brett will experience less stress at higher ABVs than a typical beer yeast.

 

[dantheman13]

The only issue I see with reusing the yeast cake is that this first beer will have a pretty high ABV which can stress yeast - at least a normal beer yeast. Maybe someone else knows if brett will experience less stress at higher ABVs than a typical beer yeast.

Yes, Brettanomyces is less stressed from ethanol than brewer's yeast. That said, I haven't heard a lot about re-pitching slurries of 100% Brettanomyces beers. I suspect it would be fine. One thing to keep in mind is that some Brett cultures (particularly from White Labs) are contaminated with brewers yeast or sometimes other yeasts/bacteria, so those can have an impact on flavor, both during the original batch, and subsequent batches.

 

[cactusgarrett]

One thing to keep in mind is that some Brett cultures (particularly from White Labs) are contaminated with brewers yeast or sometimes other yeasts/bacteria..

Yup, that's why I explicitly chose the WY strain and not the WLP one.

General update: I just took the first grav measurement and taste of this last night. After 15 days at 70-74°F, it's down to 1.015 (i think ~80% aa). I have read that some 100% brett beers are indiscernible from sacc beers, but this one isn't the case. Just the right amount of funk/tartness, likely due to the higher ferment temp. I didn't the cherry pie explosion, but it definitely was along the lines of the flavor profile of the WY Roeselare blend I use. Overall, I'm pretty stoked about how this is turning out. I was initially planning on making this a funky white stout by adding a cacao tincture and cold brewed coffee, but I'm very 50/50 on that concept still.