Cold crash vacuum?

For those of you that cold crash before racking, how do you prevent a vacuum in the blowoff or airlock and sucking in sanitizer?

As far as the airlock not touched and dripping into the fermenter.....never happened to me.

I do get the occasional suck back when removing the air lock even when not cold crashed. For that reason I buy cheap vodka for the airlock, it will only add alcohol, and won't change the taste.

I would not recommend sanitizer in the air lock. Most everyone uses water. I had trouble with sanitizer on my vessels giving it a bad taste. Now I always rinse everything after sanitizing with water. City water has a little chlorine but not enough there to worry about.

How would this airlock work any differently in a vacuum than a three piece?

Bubbles backwards rather than suck in the fluid.

S-style airlock is possible the best 3$ I have spent on brewing.

Once I cold crash I swap out the airlock and use a carboy cap. Works like a charm. No sanitizer, no O2.

Ditch the airlock and use plastic cling wrap or aluminum foil. Wrap tight and secure w/ a rubber band if it makes you feel bettter.

AnOldUR said:

Bubbles backwards rather than suck in the fluid.

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Honestly, I can not believe that I never noticed that!!! Jesus, one of those "well duh, *******" to self moments!!!

I usually just use some nice thick Al foil with a rubber band nice and tight. No biggies!

I like to use a medical air line filter.

Bull

AnOldUR said:

Bubbles backwards rather than suck in the fluid.

Click to expand...

But then aren't you just letting Oxygen into your fermentation vessel?

I'm looking for a good solution on this. Sounds like maybe a carboy cap seems to be the best way to keep it closed off without having any oxygen enter (except for the exposure time when the cap is changed).

Silentnoiz said:

But then aren't you just letting Oxygen into your fermentation vessel?

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A small amount of air does get sucked in, but there are two things that may not be true, but still roll around in my head.

First is that as the air passes through the vodka in the airlock there is some amount of sterilizing going on. (I know that gnats don't survive the trip.)

Second is a paranoia I have that my glass carboys are not rated for either pressure or vacuum. I envision the thing imploding in my refrigerator if it's sealed tight.

I've been using this method for several years and never noticed or had a judge mention oxidation in my beers, so the small amount of O2 that gets in there from the ambient air and combines with the pure CO2 in the headspace must not be an issue.

But if you're still worried, I think it was Bobby_M who did something with a balloon filled with CO2 replacing the airlock.

Silentnoiz said:

But then aren't you just letting Oxygen into your fermentation vessel?

I'm looking for a good solution on this. Sounds like maybe a carboy cap seems to be the best way to keep it closed off without having any oxygen enter (except for the exposure time when the cap is changed).

Click to expand...

Yes air will come back through the "S" air lock..It’s so minimal and will stay on top of the C02 simply because it’s lighter.

Cheers
Jay

wilserbrewer said:

Ditch the airlock and use plastic cling wrap or aluminum foil. Wrap tight and secure w/ a rubber band if it makes you feel bettter.

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Yes, just use a piece of sanitized aluminium foil. I use Star-San in my airlocks and if it gets sucked in no biggie. Not sure I agree with the above statement of most people using water....most I talk too use Star-San or cheap vodka. Water would be my last choice. There's still a layer of CO2 over the beer, so I don't worry about the little bit of O2 getting in the fermenter.

Cool, thanks for the tips! Always glad to hear what works and doesn't work for others.

I found in another post somewhere on here about this cool product:
http://www.rebelbrewer.com/shoppingcart/products/Silicone-Waterless-Airlock.html

Anyone using these and have a report? I may buy a couple.

Ok, I'm a newb...not sure why my URL didn't post.

rebelbrewer.com/shoppingcart/products/Silicone-Waterless-Airlock.html