Cold crashing

I've always have secondaried my brews but I have been reading a our cold crashing in the primary and decided to give it a try. Started cold crashing my SMaSH on saturday and by Monday it had sucked all of my sanitizer up through my 1 in blow off tube into my beer!!! WTF!! I'm guessing because of the change in the ambient temp. What's the proper procedure? Just plug it first? It takes a lot of vacuum to suck that much liquid up a 1 in. hose! Know I've got about 1/2 gal. of sanitized floating on my beer . Don't know if I should try to rack it off the top or to try to rack the beer out from under neath it!! There has to be someone else out there that has had the same problem!!

What kind of sanitizer do you use? Chances are you don't have sanitizer floating on your beer - you have sanitizer mixed into your beer - but depending on what that sanitizer is, it may not be a major problem.

I know it's a little late for this but, going forward, make sure to swap in a standard airlock instead of a blow-off tube when cold crashing. That should just bubble as the pressure changes with the temperature, instead of sucking all the fluid into your beer.

my keezer is not tall enough to fit my carboy on the shelf w/ the airlock installed, I just put a piece of sanitized foil over it works fine for me.

hpz937 said:

my keezer is not tall enough to fit my carboy on the shelf w/ the airlock installed, I just put a piece of sanitized foil over it works fine for me.

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This is what I do as well...

The 3 piece airlock will suck back the fluid in also.. I use the "S" shape airlock with grain alcohol most times and have never sucked back the fluid..

I have had "suck back" before as I am sure most everyone else has. That is why a lot of people use cheap vodka in the airlock.

I just cold crashed 5 Gal of cider last night and checked it during my lunch break. I use starsan and 3 piece airlocks. Some sanitizer got sucked in but i'm not worried. I would say it all depends on what your sanitizer is. If you use starsan like just about everyone else, you should be A-OKAY!

It is star san. So I'm hearing that it's ok for it to suck air ( using a "S" lock or foil) or to suck vodka ( using a 3-piece). Can the carboy handle the negative pressure if just plugging it? Glass or a better bottle?

We spend all this effort to to keep outside air out of our beer. Then to just sit back and let the bad air back in during a cold crash makes no sense to me.

Im no expert but I would assume the co2 would protect the beer from air being sucked back in as co2 is heavier than air

when you use an airlock and it sucks air in, it's no longer an airlock. completely useless if you're cold crashing.

i've read often that star san won't hurt in small amounts - not sure about a 1/2 gallon tho... i'd ferment and check it out tho... might be fine.

if you open ferment with well pitched yeast and you'll have a blanket of CO2 on top of your beer - provided you don't disturb it much. once you change the pressure relationship of a sealed container (airlocked and chilled) you create a relative vacuum.

I wouldn't worry about the air that might get sucked in when you cold crash, because honestly the beer is going to see a lot more air than that when you open the carboy to rack the beer. But if the cold crash is really pulling 1/2 gallon of sanitizer in through your blowoff tube, then you need set up your blowoff differently. Use a longer tube, keep the end of the tube as low as possible (i.e. at the same level as your carboy, or lower), and only add enough sanitizer to keep the very end of the tube submerged. There's no reason to have the end of your blowoff tube submerged in a 1/2 gallon of sanitizer.

CaptnCully said:

I've always have secondaried my brews but I have been reading a our cold crashing in the primary and decided to give it a try. Started cold crashing my SMaSH on saturday and by Monday it had sucked all of my sanitizer up through my 1 in blow off tube into my beer!!! WTF!! I'm guessing because of the change in the ambient temp. What's the proper procedure? Just plug it first? It takes a lot of vacuum to suck that much liquid up a 1 in. hose! Know I've got about 1/2 gal. of sanitized floating on my beer . Don't know if I should try to rack it off the top or to try to rack the beer out from under neath it!! There has to be someone else out there that has had the same problem!!

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First of all, the sanitizer and the beer are both miscible (mixable) aqueous solutions. The sanitizer is likely not a "layer floating on top of the beer". Rather, through simple Fickian diffusion, the beer and the sanitizer have likely mixed and are 1 solution now that cannot be separated out.

Secondly, when you cool the beer, the air inside contracts, and that forms a vacuum. That is why your sanitizer got sucked in. In the future, the proper procedure would be to take the blowoff assembly off after primary and put an airlock on with sufficient sanitizer to form the barrier, but not too much as to get sucked in.

However, I am not a fan of cold crashing primary, because there is still a population of yeast in solution cleaning up the beer. I usually get to around my FG, rack to secondary and condition around 66 F for 1-4 weeks (depending on the beer), then add a teaspoon of boiled gelatin per 5 gallon and cold crash for 1 week. Everytime, my beer taste great, is appropriately attenuated, and is crystal clear.

Do you stir the gelatin into the beer?

crazyirishman34 said:

Do you stir the gelatin into the beer?

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I give the carboy a gentle swirl, not too hard as to upset anything that has already settled out. Again, simple diffusion will occur, and it will mix anyways.

what is the gelatin to water ratio that you use?

crazyirishman34 said:

what is the gelatin to water ratio that you use?

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I use about 12-16 oz of water, about a pint glass. I generally boil the water for 5 minutes, add the gelatin, and boil for about another 10 minutes. I then cool the solution to room temp (don't cool it too much, or it will gel up!), and pitch .

Makes sence to me.

The sanitizer did sit on top and I was able to rack the beer out from under it losing about 3/4 gal.

CaptnCully said:

The sanitizer did sit on top and I was able to rack the beer out from under it losing about 3/4 gal.

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Did you taste it at all? Wondering if it might a little sour due to the extra acid (ph drop)!! I would let it sit and see what happens and if the starsan breaks down a little that is, what little might have mixed in

This is strange...I specifically use a blowoff tube so there is no suck back...next time, create a loop in the tube so that as the sanitizer goes up the tube, this will cause air to get in the solution and make the sanitizer fall back. I have a decent "puddle" of sanitizer at the bottom of my loop but none gets in.

Maybe drop the temp slower too

I guess that my question would be what is the point of an airlock or a blow off at that point. You are going to get outside air into the fermenter. After the beer is fermented your are worried as much if not more about oxidation then infection. So if you wanted to be totally obsessive about it get a cask breather and hook it up so it doses Co2 into the fermenter as it cools.

I use a 3 piece airlock and when I have cold crashed (only two times now so not an expert) I pull off the cap and the internal cover piece and hook up my aeration hose (the one I would generally use with a fish tank pump to aerate pre-ferment) so that any air that does get sucked in passes through the sanitizing filter. Just have to make sure to airflow is the same direction as when used with the pump.

CaptnCully said:

The sanitizer did sit on top and I was able to rack the beer out from under it losing about 3/4 gal.

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Are you saying that your Star San solution fell into your fermentor and made an entirely separate phase? As a scientist who has done a fair amount of solution chemistry, I can tell you that no two miscible aqueous solutions can stay separated in the same container, and that separation is actually impossible. Just the action of the sanitizer dropping in is enough to mix them pretty good, not to mention the fact that even a slight movement of the carboy will mix. If you think you left the sanitizer behind, I would rethink. If you started cooling on Saturday, the solution probably got sucked in that day, and then had two days (until Monday) to mix by diffusion alone, not to mention the initial splashing of the sanitizer falling into the carboy.

Drop a small drop of food coloring into a glass of water, wait two days (just like your situation from Saturday to Monday) and see for yourself. I would say you probably have more sanitizer in your "salvaged" portion and more beer in your "sanitizer" portion than you think. Good luck though. Hopefully the extra acid doesn't melt the enamel off of your teeth Just kidding, you should be fine.

Also, in the future, don't use so much blowoff sanitizer. It's not just unnecessary, it's a darn waste of good sanitizer (Star San ain't cheap!).

biobrewer:
I did not mean to mislead anyone into thinking that i got ALL of the beer out from under the sanitizer. However I could see a defined line of color change and siphoned it down to there

CaptnCully said:

biobrewer:
I did not mean to mislead anyone into thinking that i got ALL of the beer out from under the sanitizer. However I could see a defined line of color change and siphoned it down to there

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Yeah, I figured that. I'm just amazed that it formed 2 phases.