Imperial Stout Fermentation Question

NB instructions have me racking to a secondary after fermentation has slowed. Once in the secondary, its to condition for “2 to 3 months”. Question: How am I to judge if it has conditioned enough? I have read that this brew just gets better with age so i’m not in any hurry at all, i’d just like to understand why i’m doing what i’m doing. Also, after 2 to 3 months of conditioning will there still be enough viable yeast to carb bottles?

I don’t think I’d move it out of primary until fermentation is good and complete, like after 3 weeks or so. To move it to secondary is risking a stalled fermentation, as you want it in contact with the yeast cake on high ABV brews to make sure everything is cleaned up properly.

As I see it, the best reason to leave it a long time in secondary instead of storing in bottles (it really does the same thing), is that it’s too easy to crack one open too early if it’s in bottles.

2-3 months? No problem carbonating, but it’ll be slow. Even more so because of the high ABV, but it’ll work. Some people bottle with champagne yeast to make sure it does its thing. Probably not necessary, but it’s cheap insurance.

I wait at least 3 weeks before I rack my RIS. I’ll leave it in secondary for at least 3 months, usually 5-6. Bulk conditioning is supposed to help the flavors round out. I’ve never re-yeasted and have always gotten good carbonation. I also wait at least a month before opening a bottle.

If you do add yeast, go with something neutral like US-05. I’ve read of bad results with champagne yeast.

Should I think about it like this : 2 months fermentation is ok, 3 months and it will taste better, 5 months and it will be great?

Exactly - replace “fermentation” with “secondary” and you’re golden. I don’t think you’d want to leave it in primary for 5 months. In general, the longer you can leave something like this alone the better it will be. You can also age in bottles with much of the same effect, but the advantage of using a secondary in this situation is that it will all mature similarly, whereas if it is in bottles you might see variation from bottle to bottle. Think of your secondary as one big bottle in which you can age the entire batch.

BrewingRover, what issues have you heard about with champagne yeast? I have an aged lambic that I’m going to bottle somewhat soon, and was thinking of using champagne yeast. If there’s a reason to not do it, I’m all ears! I’ve put a lot of time into this one and don’t want to ruin it!

My biggest concern with using US-05 (edit - for bottling) is that a big RIS could be over the alcohol tolerance of it… Maybe one of the crazy yeasts like WLP099 would be a better choice (edit - for bottling)?

US-05 will be fine with the alcohol, but I would opt to use a british ale yeast for a RIS. I think it helps accentuate the malt a little more.

I think using champagne yeast for bottling is fine, particularly for sours since other yeasts have problems with the alcohol and the pH.

The problem with using champagne yeast for a beer is there are virtually zero esters produced (to my understanding), which are important in literally every beer style, even lagers.

To the OP, make sure you have a big slug of yeast, have a way to control the ferment temp, and to the prior points, do NOT rush the fermentation. I would leave it on the yeast for a minimum of 3 weeks, then age either in bulk or bottles for a minimum of a few months, but it will get better with age. Like years of age.

Right - I was only talking about using champagne yeast as bottling yeast, IF you wanted the extra insurance of getting good carbonation after a long secondary.

I was concerned about the comment regarding champagne yeast not working well as bottling yeast. I understand it’s a fairly common commercial practice, so if there were any reason to not use it I wanted to know.


I went looking at some old posts and found this thread. Basically champagne yeast is no better than ale yeast, but I misspoke about off flavors


I wouldn’t worry much about the alcohol tolerance, as it’s fermenting the fresh sugar you add for priming, not the finished beer.

So here’s my question - i’ve had my imperial stout sitting in secondary for a looooong time - unexpected surgery, blah blah, didn’t have the ability to bottle it. So let’s say we are talking about 8 months at this point. It looks/smells fine, so i’m going to bottle it and hope that it didn’t sit for too long. I got some champagne yeast and some priming sugar for bottling - now the question: when / how do i add that yeast? Do I add a few pebbles to each bottle prior to bottling, do I just mix it in on bottling day with the sugar…? Also, do you think the normal priming packet is going to do it in this case, or should I ramp up - the last thing I want is a bunch of bottle bombs, but on the other hand, I’d like to do everything possible to salvage this thing. I’ll be mostly bottling in 22 oz bottles, with a few 12 or 16oz thrown in if/when I run out of the larger ones. Any suggestions would be appreciated!

By the normal priming packet, do you mean the 5-oz packet of corn sugar they sell? I think that’s almost certainly going to give you too much carbonation, assuming a 5-gallon batch. Check out NB’s priming sugar calculator, and you should be able to dial in your carbonation level exactly where you would like it to be. Imperial stouts can be anywhere from low (1.8 volumes) to moderately high (2.6 volumes), but I certainly prefer them on the lower side. Totally up to you.

I’ve had best results rehydrating the champagne yeast in some warm (~80-90F) water, maybe 4 oz or so. Then mixing it in with the priming sugar prior to bottling. You really only need about 1/4 - 1/2 the packet. It’s a little discouraging to see a beautifully clear batch suddenly clouded up with the fresh yeast, but it’ll fall out no problem in the bottle.

Good luck!