I have done about a dozen batched where I have always left my beer in the primary fermenter for an extra week or two and siphon directly to the bottling bucket on bottling day. The one time that I racked to a secondary I ruined my beer (Acetobacter infection). I'm wondering if cold crashing is the proper way to go to help filter out the junk and get better looking beer. Thoughts or advice?
Cold crashing will help any yeast still in suspension to drop out. It can also encourage proteins and tannins to join and, being heavier, drop out faster.
I feel like most times I cold crash I have issues where the airlock is sucked dry or the liquid in the blow off jug gets pulled up the line. I usually use sanitizer for my airlock and blow off but what do you guys do to avoid that besides lifting up the blow off tube after it starts cooling?
@cfrobrew I always cold crash prior to racking to keg and generally my airlocks don't get sucked dry but it has happened once or twice previously. You could cover your carboy/bucket with sanitized foil for 5-6 hours till the liquids temp drops sufficiently? As I said tho my airlocks rarely get sucked dry and I keep my fridge around 36-38f.
I noticed this when I started cold crashing too. Initially I would crack the airlock open for a second but I realized that air was then being pulled into the carboy and risking oxydizing the beer. What I discovered is that if I cold crash slowly this doesn't happen. So I'll drop the temp down about 5 degrees every 10-12 hours. It'll take about 2 days to get it to the mid 30s. What I think happens (and someone can correct me if I'm wrong) is it allows the temp of the beer and air to equilibrate slowly so there's no contraction and sucking of air into the carboy.
Ideal gas law (works for fluid too)...pv=nrt In other words, pressure and temperature are directly related/proportional. Decrease temp leads to decrease pressure = suction of air/fliud from airlock into fermenter. I dont usually have suction created, but the few times its happened, it hasn't affected the final product. I cold crash, for at least a day or two, all of my beers before kegging them (I dont bottle at all nowadays, unless its to finish a keg off to put the next batch on) and wouldnt have it any other way. The drop in temp forces precipitation of more yeast and other suspended particles and helps clear the beer and reach FG efficiently. To help with cold crashing, I always add Irish Moss 15 minutes to go in the boil...if you dont use it, you should think about it!
And if you're getting contamination, then you aren't sanitizing correctly/well enough. I use bleach for sanitizing most everything when I brew or rack and have never had issues with contamination in over 20 years of brewing. Bleach is cheap and is one of the only things proven to kill a majority of microorganisms effectively, in all of its applications.
Cooling slowly seems to provide less of an issue for me too but I always pull my blow off tube and stick it back just to be safe. Like @DrMindbender said, the pressure differential is going to happen no matter what. I was more curious if I was cooling too fast or what techniques others might have. Cooling slower is probably fine for most people because there is a very slight leak into the carboy, which shouldn't oxidize anything especially after that carboy has been purged with CO2 from the yeast. CO2 is heavier so the beer will see more O2 when you transfer. Just to suffice my desire to not drink sanitizer, Ill probably just do the aluminum foil trick.
Bleach is quite effective...I've sanitized with it since the early/mid 1970s and continue to use it most of the time, having only just recently started using StarSan for a few select applications. Bleach is cheap, and very effective. If used properly, it won't corrode your equipment as commonly warned...but used improperly, it most certainly can cause damage.
With reagards to the airlock being sucked dry of sanitizer, could you not use just a bung rather than the type with the whole in it for the airlock? I haven't cold crashed my beers yet but was going to start and I was going to proceed in this way.
Just cap it with a fully-closed cap (or piece of foil) before you cool. There's practically no yeast activity at that point in fermentation anyway, especially at cold-crashing temps. No need for an airlock, just a cap.
Ah good point, I always forget about these. I bought a few and forgot about them because the seal seemed a bit iffy but this would be a good application.
What about doing this in a Better Bottle? I saw a YouTube video where the guy capped and cold crashed. The bottle looked crushed. I worry this is a recipe for disaster. Anyone else do this?
