cold crushing & blowback

[brewbucket]

After putting 6 gal carboy in a fridge, I have noticed that the liquid levels in S-shaped airlock have reversed and I think it mast have already passed few bubbles of outside air into inside of carboy.

Is it a problem and how you deal with it when you need to chill your secondary?

Would you use a solid stopper instead of airlock? Long blowoff tube? 3-piece airlock? (but this would suck the liquid inside).

 

[Hammy71]

When I cold crash I take off the airlock and replace it with a piece of sanitized aluminum foil. Your beer has alcohol in it now and is more resilient to infection. Ditching the airlock when cold crashing is quite common.

 

[DrawTap88]

When I cold crash I take off the airlock and replace it with a piece of sanitized aluminum foil. Your beer has alcohol in it now and is more resilient to infection. Ditching the airlock when cold crashing is quite common.

+1 to that. Once fermentation is done, there is no need for an air lock.

 

[michael.berta]

Personally I just use cheap vodka in my airlocks and don't worry if some falls in....

 

[theredben]

S-type airlock will work just fine. It will sterilize the incoming air. Aluminum foil will also sterilize the air, just don't use a solid stopper since the air needs to get in.

 

[brewbucket]

Personally I just use cheap vodka in my airlocks and don't worry if some falls in....

S-type airlock will work just fine. It will sterilize the incoming air. Aluminum foil will also sterilize the air, just don't use a solid stopper since the air needs to get in.

thank you for the advice, using S-type airlock with vodka ever since, no issues!