Year old sour beer on cake/trub, making second batch

[Fetus]

Last Christmas, I brewed an experimental 5 gallon batch of beer. It's a hybrid lambic/quadruple that will be eventually aged on oak and cherries. Fermented with Roselare and dosed with Consecration, Supplication, and Drie Fonteinen dregs through out the year. As of right now, the beer is still sitting in the original carboy on the trub and cake.

I'm tempted to rack this beer out and rack another 5 gallons of new wort in right on top of the previous cake, made from the same recipe. Is this ill-advised? I know it's not ideal, but I'm curious if after a year the fresh wort would be enough to revive the yeast and bugs.

Thanks.

 

[randomsample]

Your yeast viability will be low, though it depends on the temperature. 70 degrees for a year, it's probably dead. 50 degrees, there's probably enough. I'm not sure I would age on a yeast cake that long; it's fine for a few months, but I did that with a mead, and as the yeast started to turn darker brown it ruined the mead flavor.

 

[HokieBrewer]

No need to worry aging on the cake. Brett feeds on dying yeast cells. As far as viability though, I'm not sure. I haven't seen anything concrete regarding racking on sour cakes.

 

[mcarb]

I racked onto the cake from a batch of sour that had been going for four months. It worked great.

 

[Fetus]

The carboy has sat in room with an ambient that bounces around 62-68 degrees. The yeast cake doesn't appear to look brown, and according to lambic information I've read, the brett and bugs feed on the breaking down yeast and trub, and helps provide complexity.

I suppose, worst case scenario I can dump another pack of Roselare in if I don't get activity.

 

[Calder]

The bugs and brett will be fine; maybe just coming into their own. The sacc is questionable. I just racked a 13 month Flanders on to some fruit. I had not touched the Flanders since inoculating it. It took 3 days to get any action from the new sugars, and a couple more days to really get going.

Give it a go. Worst case, you can pitch some sacc after a few days if you get no activity.

Others might be able to give you more advice, but I understand re-using sour/wild cakes, results in a lot sourer beer; probably because the bugs are in a high proportion. You might want to just use a quarter of the cake.

An alternative would be to take a quarter of the cake and make a starter to determine if the sacc is still going.

No isses with keeping the beer on the cake for a year. That's how Lambics are made. The cake provides food for the Brett.