Transferring an Active Brett Fermentation

[Easycreeper]

Hey, all.

I've got a small situation going and I'd like some advice if anyone has experience or plain old input.

So, I've got a Brett fermentation going fairly slowly from a co-pitch between WLP530 and WLP648. The 530 dominated from an OG of 1.111 down to 1.030, but quit because of a faulty temp controller keeping temps too low instead of the planned ramp up.

Now the Brett is in the beginning stages of forming a pellicle (just a few small white spots) and I'd like to get the beer off of the yeast cake. Of course, I'm still OK for a few weeks since tomorrow marks the second week since the beer was brewed.

The question is: Can I transfer this beer without running the risk of halting the Brett fermentation?

 

[RPh_Guy]

Transferring won't stop Brett.

FYI getting it off the cake isn't necessary for autolysis concerns.

The alcohol tolerance of the Brett is more concerning. Looks like your beer is 12% ABV, the upper limit listed by white labs for that Brett strain.

 

[gordonmonaghan]

You can transfer it without risking anything. Or you can let it sit for a while. The advantage to transferring now is any oxygenation will be taken up by the Brett, and probably the sacch. I would guess the 530 petered our not because of temperature, but because it has eaten all the available sugars. Of course, I have no idea what your mash temp was, and so can’t really guess how fermentable the wort was. Also, that’s a lot of alcohol already, and that will slow done the yeast, too.

In summary: transfer now or transfer later.

 

[Easycreeper]

@RPh_Guy and @gordonmonaghan

Thanks for the replies and insight.

Initial mash temp was 152F and fell to 138F since it was mashed overnight. Should have been pretty fermentable, but who knows?

Yeah, the ABV tolerance his a concern. For some reason, my efficiency took a big jump this time, so much so I cut back the boil time to help compensate. Tried pitching Belle Saison late into fermentation as well to no effect.

I may be looking at something borderline undrinkable this time because of a high finishing gravity and low hop rate. Unless the Brett can produce enough acid and funkiness to salvage the beer, if only as a pointed lesson of yeast limitations.

 

[RPh_Guy]

Well... I guess you could dilute it.

Pull 25mL and dilute it to 50%. Confirm 1.015 gravity.
Put the 50mL sample in a jar. Give it 2 weeks, see if gravity drops at all.
Then you'll know whether diluting it will help ferment more in addition to lowering the gravity directly.
Sort of a "forced fermentation test".

I don't think Brett will be very active at 12% ABV. I think it struggles above 8% from what I've heard. So you'd be looking at possibly diluting the beer down to 7-8% ABV, which would immediately put gravity below 1.020.

 

[madscientist451]

If you are considering diluting the beer to save it, perhaps brewing a similar beer with a lower gravity and diluting the 12% beer with wort would be a better choice than just using water.

 

[Easycreeper]

Diluting may be the answer here as you guys have said. I may have to boil some additional hops in water to maintain around 15 IBU if I go the water only route. I do like the modified forced fermentation method mentioned.

Going the second beer and blending route may add the complexity I missed out on in this beer. From the overly sweet sample I had last weekend (1.037), the Brett character hadn't come through much at all. Ill have to order some additional Brett for this.

 

[RPh_Guy]

diluting the 12% beer with wort would be a better choice than just using water.

Why? You'd need to dilute even further by using wort because of the alcohol from the addition.

 

[madscientist451]

Adding water to the current beer will bring down the ABV and possibly allow the Brett to develop, but it will also change the body/mouthfeel and flavor of the beer. Adding a 1.030-1.040 wort will also bring down the ABV, but the change in body and flavor will be diminished. The goal would be to have the ABV, after the new wort fermented out, in an acceptable range for the Brett to have a chance.

 

[RPh_Guy]

Whether you use wort or water to dilute to the same eventual ABV, It'll have the same amount of grain in it, so the same body/mouthfeel/flavor either way.

 

[Easycreeper]

Just a quick update.

Going to leave it be for the moment and see what happens. It's doing something, but I'm hesitant now to say it's a pellicle forming. The Tilt registered another point drop in SG overnight and there are little colonies of bubbles scattered over the surface. Maybe the diastatic characteristic of the Belle Saison is finally showing itself?

Could be just finishing up the last point or two and off gassing from the slight temp fluctuation. Guess we'll see in a week or so...

 

[505-Brewer]

Brett takes time for flavor development. Leaving for 3 months then taste it. Keep your airlock filled.

 

[Easycreeper]

Brett takes time for flavor development. Leaving for 3 months then taste it. Keep your airlock filled.

Thanks for the input. Nervous about leaving it on the cake for so long and hesitant to transfer to another vessel for fear of stopping whatever is happening.

@RPh_Guy is there no issue with Brett and autolysis? Even when sacc is involved? I've experienced autolysis in an imperial stout left in primary for three months, but that was sacc only.

 

[RPh_Guy]

You can leave mixed fermentation beers on the cake for years. Brett eats the decaying cells to make more flavor.

Edit: It's easy to pull Brett from unpasteurized bottle dregs, so no, transferring it won't stop it, but I like to leave mine on the cake.

 

[Easycreeper]

You can leave mixed fermentation beers on the cake for years. Brett eats the decaying cells to make more flavor.

Learn something new every day with this hobby. Guess I'll leave it be and see where it goes. Thanks!

 

[gordonmonaghan]

How’s it looking now?