my blow off tube went in reverse

I cold crashed my beer in the chest freezer down to 43 to drop out the yeast before transferring into the keg. Well at some point while it was cooling it decided to suck up the water out of the container and about a half gallon of it is sitting on top of the beer.

It's clearly separated having not mixed together hardly at all. Can this beer still be salvaged? If I leave it in the fermentation chamber, not mix it up by moving it and transfer most of it until it gets down to the water into a bottling bucket (prob 4 gal more or less) will it still be safe? Or is this just a loss? I could also throw it in a keg.. thoughts????

First the why: You cooled what was in your primary, causing the pressure to drop to a partial vacuum and pulling your blow off solution into your beer.

Not sure what to do. I'm guessing you used something sterile as your blowoff solution (starsan, or the like). A couple options I would suggest you can TRY (certainly no guarantees) would be to siphon the solution off of the top of your beer and carry on as usual or to leave it on your beer and siphon the beer away when you bottle. Just try to minimize mixing.

Anyone have any other ideas? Are my ideas stupid? Like I said, I have never done anything like that, nor do i make any guarantees.

freisste said:

First the why: You cooled what was in your primary, causing the pressure to drop to a partial vacuum and pulling your blow off solution into your beer.

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That's what I'm wondering.

OP, was it star san in the blowoff jar? Obviously, this is a less than ideal situation, but there's not much you can do about it now. If it was star san in the blow off jar, take solace in that. Next time, replace the blow off tube with an airlock before cold crashing your primary.

If whatever got in the brew was sterile, there is no harm in continuing the process. Worst case you lose a couple bucks in priming sugar and bottle caps. Best case you minimize how much of the blowoff solution you bottle and the beer turns out pretty good all things considered.

This brings up a question because I am going to cold crash very soon. Is there a. Airlock that works both ways? I thought they kept baddies from getting in while letting the closed system "exhale". Do they keep baddies out while letting the closed system "inhale"?

If the solution in the airlock is sanitizer, and the airlock's sanitized, nothing should be able to get through the solution.

I use a 3 piece, not the s-type. The center column of the 3 piece is shorter than the outer tube. It seems like it is going to pull solution into my brew. Maybe I will just have to be careful of the level of the solution...

Is there a specific style that works well? Should I just relax and use my 3 piece?

Next time you cold crash remove the blow off tube or airlock and just cover with some sanitized aluminum foil works great never had any problems with it. Good luck with the beer I bet you can save it.

Good idea with the sanitized foil. That is probably what I will do in a few days. I was also thinking of using my very convenient chest freezer as the OP did, but was worried about destroying my airlock. And possibly sucking the seal into my carboy because of the partial vacuum.

I don't have any good ideas about what to do with your present situation, but I am curious if you had your blow-off container elevated when this mishap occurred? It seems to me it would be unlikely or impossible to suck 1/2 gallon back into the fermenter if the blow-off container is on the same level as the fermenter. On the other hand, if the blow-off container is elevated, then it would only take a small amount of suck-back to start a siphon from the blow off container back into the fermenter, causing the blow-off to all be dumped back into the fermenter.

Thanks for the feedback. The container had sanitizer in it. Starsan. It was level with the fermenter but the weird thing is that this was a 10 gallon batch and it only happened to one of them.

I think I'm going to siphon from the bottom and stop before the water gets there and bottle as usual. In the future, I will definitely switch to an air lock or foil cover before cold crashing. It was pumpkin beer btw.
Thanks again!

Actually, now that I have had some time to think about it, don't use an airlock in the freezer. I think it will freeze.

DeafSmith said:

I don't have any good ideas about what to do with your present situation, but I am curious if you had your blow-off container elevated when this mishap occurred? It seems to me it would be unlikely or impossible to suck 1/2 gallon back into the fermenter if the blow-off container is on the same level as the fermenter. On the other hand, if the blow-off container is elevated, then it would only take a small amount of suck-back to start a siphon from the blow off container back into the fermenter, causing the blow-off to all be dumped back into the fermenter.

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not with the right temperature differential.

eastoak said:

not with the right temperature differential.

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Yeah, I was only thinking about beer and gas shrinkage due to temperature, but I think the largest factor is the absorption of gas as the beer cooled and I can believe that could account for 1/2 gallon or more of "shrinkage".

Also depends on headspace. While the liquid will contract slightly, the gas accounts for most of the pressure drop. A fermenter filled close to the top will have a lower pressure drop than a fermenter only half full. Also depends on temperature drop. If it was warm going into the freezer, there would be a bigger disparity between initial and final pressure.

But assuming that it was at fermentation temp, say mid-60's at the beginning, and cooled by about 30º F when crash cooled, then the beer should only shrink about 1% and the gas only about 6% (PV=nRT). So for a 5 gallon batch with a one gallon headspace, that only amounts to .05 + .06 gallon = .11 gallon, or less than 1/2 quart. I have to believe that gas absorption at the colder temp. is the biggest factor. The only way I can think of to analyze this is by looking at a force carbonation chart like this one:

http://www.kegerators.com/carbonation-table.php

There is no zero pressure column in the chart, so use the 1 PSI column. Volumes at 65º F = 0.88 and at 34º F = 1.68, a difference of 0.8 volumes, or, for 5 gallons, 4 gallons of gas. Now obviously all of that would not be absorbed in a couple of days of crash cooling, but still indicates that it may be the biggest factor in the "shrinkage".

There was at most 1 gallon of head space, maybe less. It was a very full fermenter. The other fermenter had about a gallon more head space and didn't have the problem.

I ended up racking from the bottom into a keg and have it under pressure as we speak. It smelled great in the keg and well see how it turns out in few weeks. I'll probably end up bottling it with the beer gun later on.

As luck would have it, this will likely be the best beer you ever had. Good luck trying to replicate in the future

I ran into this last year.
Sucked in a 1/2 quart of a lightly dosed Iodophor solution. Live and learn I guess.
Mine was barely drinkable, it doesn't take much Iodine to ruin a batch, very strong aftertaste.
I switched to starsan soon after, I prefer the taste of Starsan to Iodophor

mredge73 said:

I ran into this last year.
Sucked in a 1/2 quart of a lightly dosed Iodophor solution. Live and learn I guess.
Mine was barely drinkable, it doesn't take much Iodine to ruin a batch, very strong aftertaste.
I switched to starsan soon after, I prefer the taste of Starsan to Iodophor

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You say it was undrinkable (which is certainly believable). Do you remember if it mixed? OP was able to siphon from under the layer of sterile solution.

I'm imagining a giant Black and Tan...

Now imagine drinking that much black & tan...

freisste said:

You say it was undrinkable (which is certainly believable). Do you remember if it mixed? OP was able to siphon from under the layer of sterile solution.

I'm imagining a giant Black and Tan...

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I didn't notice (or expect to see) any separation, the Iodophor solution was just slightly lighter in color than the beer. Also, 2 pints is not that much in a 5 gallon batch. One thing is for certain, Iodine has a very distinctive taste and I could taste it in every beer. Starsan solution is just plain sour, I probably would not even detect it once mixed in. The beer would just be a little more acidic. OP said that he sucked this in so I wouldn't worry that much, I am sure the taste will affected some but not enough to ruin it.

Found this excerpt from mixing muriatic acid that could explain the separation:
Acid is denser than water and will sink through the water. If water is added to acid, it will float on top of the acid.

Interesting. Not sure if it separated, though. It sounds like it ever mixed...

I certainly agree that iodine has a strong and distinctive taste. Sorry about your brew and good luck to OP.

I actually have a spigot valve on the top of my fermenter that my blow-off tube is connected to. When I begin cold crashing I close the valve. Super easy and maintains an air-tight seal.

I'm not saying that is a bad idea, but if you are going to close the valve, why use the tube at all?

freisste said:

I'm not saying that is a bad idea, but if you are going to close the valve, why use the tube at all?

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When the valve is open it serves as the blow off tube. I could just leave it open, sure, and there probably wouldn't be a problem, but with it set-up as a typical blow-off tube going into sanitized solution it keeps anything from being able to enter the fermenter. When I close it I usually remove the tube.

Got it. Sorry. When I read it originally it sounded like you had a "foolproof" idea for a blowoff tube that couldn't work in reverse. Apparently I am the fool.

Gameface said:

I actually have a spigot valve on the top of my fermenter that my blow-off tube is connected to. When I begin cold crashing I close the valve. Super easy and maintains an air-tight seal.

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Does the lid on the fermenter get sucked down, or do you have trouble getting the lid off due to a vacuum in the fermenter?

I wouldn't think so.

freisste said:

I wouldn't think so.

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Don't know what happened, but I lost my second sentence.

If it happened, you could just open the valve.

DeafSmith said:

Does the lid on the fermenter get sucked down, or do you have trouble getting the lid off due to a vacuum in the fermenter?

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The lid does get pulled down a little, but nothing serious. In the past I worried about it and would open the valve with the tube pulled out of the solution but decided it wasn't worth sucking in oxygen just to relieve the pressure (vacuum). On my last brew I didn't open it after I started cold crashing (a Scottish Ale that was already at 53F) and everything was fine.