Cold Crash and Sanitizer Contamination

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Sep 3, 2010
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Denver, CO
Hey guys,
So I ferment in a keg, in a mini-fridge so I can temp control the fermentation. I use a gas line dipped in a bottle full of sanitizer (star san) for the blow off. Well, this time (for the second time in a year! šŸ˜”) I did not remove the blow off line when I cold crashed, and due to science (physics? Chemistry?) The change in temp causes the sanitizer to get sucked up into the keg. I guess a couple questions. Is the beer safe to drink with star san in it? (12 oz to 3.5 gal ratio) ( it's a golden ale, but transferred to pineapple, so hoping that masks the flavor šŸ¤žšŸ¤ž) And should I be fermenting with a pressure valve of sorts? Maybe this will help me remember to not be such an idiot... Oyyyy.
Appreciate the feedback?
I did nearly the same thing once. When transferring to keg I just tried to avoid that bit that for me was noticeable as clear liquid on the top of the beer (could see it easily in the glass carboy). no issues with the beer flavor or anything. Maybe you can transfer it to another keg for serving? I donā€™t think it will hurt you but would guess that amount could somewhat impact mouthfeel at the very least.
I had a pint sucked into 5 gallons of Dunkelweizen once. It tasted a little more "acidic," but otherwise, drinkable.

After that goofup, I bought this. Worth every dime.

Unless it sucked up more than a pint, I doubt you'll notice any difference in the beer. I've had it happen more than once, never noticed anything.
The photo in post #5 shows a one gallon juice jug, but you can use almost anything that will seal air tight. Drill two 1 1/2 inch holes in the cap. Put rubber grommets in the holes and plastic barbs in the grommets. Attach a piece of 3/8 inch tubing to one of the barbs inside the jug. Attach your blow off tube from the fermenter to the outside of the other barb. Run another tube from the outside of the first barb to connect to whatever you want to downstream (I usually hook it up to a keg to purge, but you could run that tube into a second jug to harvest more CO2, a jar of starsan, or stick an airlock in that grommet). It doesn't matter what size the fermenter is. Here is another view:

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I made up a similar device to capture krausen while allowing fermentation gases to purge a pair of kegs. I used a PET jug with a pair of 1/2" barb to 1/2" thread fittings and a John Guest PTC to 1/2" male thread. I on the inside of the lid I used a 1/2" coupler cut in half to screw onto the pair of barb adapters while the PTC came with its own backing nut. A wrap of electrical tape to ensure the lid is sealed made it all work, and this view shows why I built it :)