Help Carbonating a High Gravity Eisbier

[CenturyStanding]

So, I'm looking to try a recipe for a high gravity Scotch Ale that is then frozen and separated like an Eisbock to fortify the strength and concentrate the malty deliciousness, just as an experiment. The final ABV after freezing and concentrating should be somewhere between 15-20%, if calculations are accurate. I would like the final product to be carbonated but the freezing will kill the yeast and I don't own a kegging system to force carbonate.

Would I be able to pitch a small amount of champagne yeast and sugar into the beer, bottle it, and carbonate it that way? Would champagne yeast be able to tolerate an environment of 15-20% alcohol? Would it be more effective to carbonate it naturally in some sort of a cask system in bulk and serve it with a gravity tap?

Any advice you have would be great. All of my beers have been bottle conditioned to carbonate, but I've never brewed anything where the yeast would die, so I'm not sure what the best method is to proceed.

 

[Scimmia]

I'd be more worried about the champagne yeast consuming the fermentables left by the original yeast, potentially creating bottle bombs.

 

[TipsyDragon]

what makes you think the freezer will kill the yeast?

 

[CenturyStanding]

what makes you think the freezer will kill the yeast?

I thought yeast died below freezing? No? I could be wrong, like I said, I've never been in a scenario like this.

Another thing to consider, though, is that the yeast might get left behind in the frozen slush.

 

[cimirie]

I wouldn't worry about the freezing killing off the yeast. Sure- some my die if punctured by ice, and some may definitely get trapped in the frozen slush. But if you give you "eis-scotch" a long enough timeline with which to ferment, you should be OK. The only thing I'd worry about is if you really do hit 20%, the alcohol content might kill the yeast.

On a side note, I'm actually making an apple brandy/schnapps for the winter that uses a 10% cider as a base. How are you going to go about freezing / separating the concoction?

 

[CenturyStanding]

On a side note, I'm actually making an apple brandy/schnapps for the winter that uses a 10% cider as a base. How are you going to go about freezing / separating the concoction?

I'm going to ferment it in primary for a decent while, try to get the beer fairly dry so the end result isn't too sweet (as Scotch Ales are generally sweet to begin with). Then, when it seems completely fermented through and the yeast seems relatively settled, I'm going to siphon into a Better Bottle carboy and put it in the freezer overnight.

Once it's solidly slushified, I'm going to cover the top of the carboy in cheese cloth, then turn it upside down over a sanitized bottling bucket and leave it there for a little while (I think most Eisbock recipes say an hour). Hypothetically, the alcohol should slowly drain through with the solid being held behind by the cloth.

Then, once the slush thaws, you could see how much quantity you have of each, check the gravities, etc., and blend to get the desired ratio if you seperately too much.

Based on a homebrewing video I saw, they said the left over thawed slush was colored, but was pretty much just water.

If I get a chance later I'll post up the video. It was super helpful and had pictures as to how they rigged up a system to separate the ice and alcohol.

 

[Scotty_g]

If you're worried about having viable yeast to bottle with, save some of your primary trub or starter slurry and pitch that in with the priming sugar. That's pretty common to do on big beers like tripels that have a high ABV and with extended aging that can take its toll on the yeast.

If you find a yeast that has an alcohol tolerance close to your desired ABV after icing, it won't eat up too much of the sugar. We did that with a sweet mead and it turned out very nicely. Also, I don't know how much of the sugars remaining in the wort will be fermentable...that's why you have to add priming sugar.

If you want a final ABV higher than the yeast's tolerance, you *could* use some high-tolerance, eats anything yeast like champagne. I *would* worry about that over-drying the beer. In this case, I'd say you have an excuse to buy kegging equipment.