SO I would like to cold crash the beer in my fermenter. I don't really have a way to do it right now but its supposed to be about 35 degrees outside tonight. I put the fermenter on the porch for the night would that do the trick? If I brought it back in and the temp went back up to 60 or so would that screw things up in any way? Thanks.
Cold crashing
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The only reason to crash is for a lot of the yeast and break to drop out of suspension. The chill tonight should do it, if not get it into the bottle/Keg and chill it then. 
cold crashing takes time, one night isn't going to make a huge difference. I think you'd be better off to chill the fermenter in a tub with ice water down to 35f or so (or buy a fridge on craigslist and put the fermenter into it) and use the gelatin trick. Gelatin will work it's magic in a two or three days instead of a couple of weeks for cold crashing.
flars
Well-Known Member
Have you confirmed that FG has been reached? A slowly finishing fermentation will keep particles suspended by the CO2 being produced. Nothing worse than have the fermentation finish in the bottle a month later.
Not sure where this came from but cold crashing does not take weeks. I cold crash in usually 24 hours, maybe 36. It doesn't take weeks. I'll usually start the crash and let it go for 12 hours, add gelatin, then continue crashing for another 12-24 at 38*F.
Bottle conditioning is different. Bottles could take a couple of weeks to clear up once they're in the fridge, depending on multiple variables.
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I disagree with this, too. Cold crashing will give you some pretty good benefits in just 24 hours (or overnight in this case).
As long as the beer won't freeze you'll be OK (assuming you've reached terminal gravity, as already mentioned by another). When you bring it inside to bottle/keg if it's warm inside it won't hurt anything. But, if you're just going to cold crash, then bring it inside and NOT bottle/keg it, I wouldn't bother.
Time (or gelatin) will also do the trick in terms of clarity.
Cold crashing for weeks is called lagering 
SoCal-Doug
Well-Known Member
Cold crashing results vary and depend much on the recipe. Some will clear quicker than others. Some will never clear.
Get it as cold as you can without freezing it for a day. At least < 40F. If its warmer it just may take a bit longer. A tub with water may hold cold enough for a day or so (especially with your evening temps). You can also add some ice packs during the day. Rotate a few back into the freezer each evening.
Take a teaspoon of unflavored gelatin and dissolve it in a cup and a half of 140F-150F water (do not go hotter, it can render the gelatin useless). Give the fermenter a little swirly-swishy to get the liquid moving. Dump in your gelatin. Hurry up and wait.
If you want to keg it at this point. Go for it. The stuff that settles will come out with the first pint or two. If you want it clear before you keg, that's fine too. Drink something else for a few days to a week.
I'm not sure I would want beer go from 30's to the 60's repeatedly. Might be ok, might not. That knowledge is beyond my pay grade.
Get it as cold as you can without freezing it for a day. At least < 40F. If its warmer it just may take a bit longer. A tub with water may hold cold enough for a day or so (especially with your evening temps). You can also add some ice packs during the day. Rotate a few back into the freezer each evening.
Take a teaspoon of unflavored gelatin and dissolve it in a cup and a half of 140F-150F water (do not go hotter, it can render the gelatin useless). Give the fermenter a little swirly-swishy to get the liquid moving. Dump in your gelatin. Hurry up and wait.
If you want to keg it at this point. Go for it. The stuff that settles will come out with the first pint or two. If you want it clear before you keg, that's fine too. Drink something else for a few days to a week.
I'm not sure I would want beer go from 30's to the 60's repeatedly. Might be ok, might not. That knowledge is beyond my pay grade.
Someone please correct me if I'm wrong, but if you bottle at cold-crash temperatures (35-40), wouldn't you need to adjust the amount of priming sugars down as the colder the beer, the more dissolved CO2 present?
thehaze
Well-Known Member
Yes, you need to adjust the priming sugar. It will usually be much less.
I use https://www.brewersfriend.com/beer-priming-calculator/ and it worked great for the last 5 batches.
You could also cold crash for 2 days and leave the fermenter at room temperature to warm up, before bottling/kegging.
What your describing is exactly what I do, and is an effective way to use gelatin. Actually I usually let the gelatin set for 3 days, but pretty much the same idea. A pure cold crash, without gelatin takes a long time to clear the beer. The last time I did it, it was easily two weeks before it was crystal clear. Then I discovered gelatin and never looked back.
To be truthful I've never checked it after one day, so maybe your right and there are diminishing returns over time. I'm always shooting for that crystal clear beer though.
flars
Well-Known Member
You would use the highest temperature the beer was at at the end of fermentation when CO2 production ended. The CO2 produced during fermentation leaves solution faster at warmer temperatures. The amount of CO2 in solution does not increase after fermentation when the temperature decreases during a cold crash. The lower temperature just decreases the rate CO2 leaves the solution.
When I cold crash in my fermentation chambers it sometimes takes as long as 20 hours or so to get the temp down. Typically I'm crashing to 32 degrees, sometimes a tad warmer. This with beer that starts in the mid-60s.
I don't know how long "overnight" is--6 hours? 8 hours? 10?--but depending on the temperature at start, I don't think it's going to get there overnight.
You could maybe accelerate it by using a fan to blow that cold air over the fermenter. That would create a wind chill which would more rapidly cool it.
I don't know how long "overnight" is--6 hours? 8 hours? 10?--but depending on the temperature at start, I don't think it's going to get there overnight.
You could maybe accelerate it by using a fan to blow that cold air over the fermenter. That would create a wind chill which would more rapidly cool it.
+ 1 to ^This^
You don't gain CO2 as the beer gets cold. When using any priming calculator you have to use the warmest temperature the beer reached during fermentation as it is that temp that determines how much CO2 is left in solution.
I have not used gelatin yet, but plan to soon. Funny thing is that most of my beers have a long time to cold condition waiting for a spot in the keezer. I have six kegs, three in the keezer and usually two in the fridge in cold storage. I like to brew, and my son and I can only drink so much beer. A good problem to have.
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