How to Cold Crash an Imperial Stout?

Question

During my first all-grain (an Imperial Stout recipe a friend and I invented), I managed to forget adding Irish Moss towards the end of the boil. After 3 weeks in primary, I've verified that fermentation has finished through consecutive days of gravity readings and I'm trying to decide what to do next. OG: 1.080, FG: 1.012, and the recipe I have written down somewhere if it's needed with regards to my questions.

After reading around lots of books, forums, and wikis, it seems no one agrees on cold-crashing, so I'd like to ask some more-specific questions.

I've read that cold-crashing will clear up your beer by causing yeast and other solids to settle to the bottom. Some have argued that this is an unnecessary step for a stout, but I'd like to put in the effort to minimize bottle trub and cloudiness after in-bottle conditioning. So my questions are:

1. Can I cold-crash with the beer still in the primary fermenter bucket before transfering to secondary? (My thoughts being that I can siphon from the bucket into the secondary carboy without moving it from the fridge and agitating the beer)
2. If so, for how long and at what temperature should I cold-crash this imperial stout ale? The yeast used was Wyeast 1056 (American Ale).
3. My fridge has other food in it, too. I know there will be a suck-in effect created from the pressure differential that arises when cooling a sealed container to match a new environment's temperature, and I realize this could cause the bucket to 'suck in' potential contaminants or flavor-affecting aromas from whatever else is in the fridge. Is this a deal-breaker for cold-crashing?
4. I plan to dry-hop for a week as another experiment right before bottling. Is there a problem with racking to secondary AFTER cold-crashing my primary bucket, raising the temperature back to 68F, then adding my sanitized and weighted hop bag?
5. Will this process have a substantial effect on carbonation? If so, should I pitch more yeast or increase the amount of priming sugar I use before bottling? I do plan on aging this beer for a long time in the bottles, so if cold-crashing will just cause the beer to take longer to carbonate, that is not a problem.

Answer 1

Cold crashing will definitely reduce the amount of yeast found in the bottle. And with less yeast in suspension there will be less floatables to reflect light, meaning your beer will appear darker than it would had you skipped cold crashing.

I agree with @cleber in that you definitely will need extra time to properly carb up your bottles but everything should turn out okay.

As to the second part of your question. I would crash at ~40F for not more than a week. Really 3-5 days should be sufficient to drop a lot of suspended yeast.

As for sucking in contaminants. It really depends. I wouldn't worry too much about it. With the flavor profile of the stout being what it is, I don't think you would notice anything even if for some reason something did happen.

Good luck!

Answer 2

I don't have experience in cold crashing, so can't answer all the questions, but here are my 2 cents:

I wouldn't worry about yeast on the bottles on a imperial stout, you probably won't see or taste any of it due to the roasted malt flavors.

For the same reason I wouldn't do dry hopping, you won't notice the smell of the hops due to the roasted malts and you will loose some of your beer to the hops.

--- Edit ---

It seems our fellow North Americans brewers did it again and created an style called 'Black Ale' which is a Porter/Stout/Imperial with a large load of hops. I stand corrected, go ahead and hop your stouts. In the end, freedom to experiment is in the very soul of homebrewing, the next time I say otherwise please ignore me :)

--- end of edit ---

my stouts usually take double the time to carbonate, I put the regular amount of sugar for the style.

Wouldn't put more sugar due to the danger of bottle bombs. Pitching more yeast kind of defeats the whole cold crashing thingy.