Hi there. I’m brewing a pretty simple American Amber Ale. I’ve been reading about primary fermentation and the conditioning phase that takes place afterwards. It’s my understanding that this conditioning phase cleans up some of the bi-products the yeast produced during the primary fermentation.
My beer has completed primary fermentation and has been in the primary vessel for 5 days. It has reach terminal gravity. Can the conditioning phase take place at 35 degrees F, or does this phase need to happen at fermentation temps?
Normally what I do is once the beer reaches terminal gravity, I crash it to about 35 degrees F for a day, then rack to a keg, put it under pressure, and then let it carbonate for another 1 - 2 weeks at 35 degrees F. I’m trying to determine if this process will satisfy the conditioning phase, or if I’m skipping that phase by crashing the beer to 35 degrees F to quickly after primary fermentation completes.
Once fermentation is complete and the desired terminal gravity has been reached, it’s good practice to let the beer stay in contact with the yeast cake at fermentation temps, sometimes even increasing the temp by a couple of degrees helps the yeast mop-up some of the by-products produced during fermentation. Sometimes, if everything is done right the yeast has very little to mop-up, but depending on the yeast strain and other variables, often it’s just good practice to hold the beer at fermentation temps for a couple extra days, after the beer has reached terminal gravity.
So lowering the temp on the beer right after it has reached terminal gravity will decrease molecular movement and will slow down chemical reactions, thus, making it harder for the yeast to mop-up any of the undesired by-products produced during fermentation.
+1. I condition mine warm when necessary. If you train your senses, you’ll know to look out for things such as diacetyl (buttered popcorn aroma), DMS (corn or vegetable aroma), acetaldehyde (green apple), and sulfur (farty). These things can be cleaned up by yeast much better at warm temperatures than cold. And typically, they only need about 3 days, plus or minus. After that, you’re fairly safe to crash it cold to 35 F or whatever. The cold crash is primarily used to drop out the yeast and make the beer closer to crystal clear. If you care more about flavor and less about clarity, then it’s probably better NOT to chill the beer at all before bottling/kegging. If you care about both, then patience will give you the greatest reward. Sit back, relax, allow the yeast to do its thing. Try not to rush it.