I have a question about using a blow off tube.

Awhile ago I made a coffee porter and during primary, the airlock blew straight off, even using a 6.5 gallon carboy. Gunk everywhere. I learned my lesson from then on that I should use a blow off tube most of the time. Better safe than sorry.

My question though is regarding the set up of a blow off tube. The tube fits snugly into the primary and is leading out into a 5 gallon stainless steel pot. I did not put any fluid in the pot, no sanitizer, no water, nothing. There has been a bit of blow off, the top of the carboy is coated as well as the beginning of the blow off tube in the fermenter. Only a bit leaked out, hardly enough to cover the blow off tube in the pot. Since I didn't use any water or sanitizer in the pot, is there any risk of contamination?

I doubt it. You need to get some water in there to keep oxygen out though. Escpecially if primary is coming to an end. Everything should be fine, just dump some water in the pot. Next time do that from the get go.

You have a small chance of infection, but mostly you are exposing you beer to unnecessary air. The whole point of an air-lock and a bung is so you can eliminate Oxidation of your beer which leads to a dull cardboard flavor. Put some sanitizer solution, vodka, even just plain ol H2O and you'll cut down your chances of infection and oxidation by 95%.

Hell you've worked this hard for beer, don't spoil it on skipping the final steps!

As far as I know, because fermentation CO2 constantly pushes air out of the carboy and through the blow off tube, dust and other particles that cause contamination cannot get into your carboy. So, as long as there is CO2 being produced there should be little risk of contamination. Still, it isn't much of a bother putting water into the pot so I'd do it.

Better yet, the blow off tube should be going into a container with some sanitizer just to be safe, not just water.

I think there's roughly 0% chance of a microscopic organism blowing up the tube and into your beer.

The liquid in there will keep macroscopic organisms from crawling in, though. Ask me about the dead ant in my airlock! Glad I had it full of vodka.

I don't think there's any reason not to use plain water in a blowoff jar, but I usually use sanitizer just because it's available, so why not? For an airlock, where you're a lot more likely to experience suckback, vodka or sanitizer is more important. But, again, outside of suckback, I don't think there's any real risk.

zeg said:

I think there's roughly 0% chance of a microscopic organism blowing up the tube and into your beer.

The liquid in there will keep macroscopic organisms from crawling in, though. Ask me about the dead ant in my airlock! Glad I had it full of vodka.

I don't think there's any reason not to use plain water in a blowoff jar, but I usually use sanitizer just because it's available, so why not? For an airlock, where you're a lot more likely to experience suckback, vodka or sanitizer is more important. But, again, outside of suckback, I don't think there's any real risk.

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I agree. I use plain water in my blow off jars.

I use Starsan for my blow-off since I have it from brew day clean-up, but it also makes it easy to tell at a glance how much CO2 is coming out by the amount of bubbles in the container.

Bricks41 said:

Better yet, the blow off tube should be going into a container with some sanitizer just to be safe, not just water.

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All I have ever used is just water (no star-san, no nothing) in the jug I use for my blowoff tube. I've brewed many a beer and never had a contamination issue.

I do use a little star-san in my 3-piece airlocks though. Since there is always a possibility of some of that dripping in to the beer.

Gary

GASoline71 said:

All I have ever used is just water (no star-san, no nothing) in the jug I use for my blowoff tube. I've brewed many a beer and never had a contamination issue.

I do use a little star-san in my 3-piece airlocks though. Since there is always a possibility of some of that dripping in to the beer.

Gary

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I use star-san or perhaps a bit of One-Step (no foam) just in case. Recently with the cooler weather, I start the carboy in the garage. From pitching, it will drop another 8-14F which creates some suction and most recently moved it to where the hose came out of the liquid and there goes an ounce or so of solution up and into the carboy LOL oops! Had another brew that I put the 3-piece airlock and took me a second to figure out why the inside piece was sucked down on the hole. I just play it safe. Cheers!!

This is all very reassuring. Made a scotch ale and don't want to lose it this time. It's been about 7 days so I think I can take this blow off tube and replace it with an airlock.

Once you have very obvious fermentation, if it doesn't blow up in say 3 days, you are probably good (depending on the temp)

It's been fermenting for 7 days at 65/66. I'd say most of the fermentation has passed, the top is caked with residue and though I can't see it, the krausen might have fallen in by now. Safe to put an airlock on it right?

I think so.

Or just leave it be. The blow off tube in a jug with water/soloution/fluid is an airlock.

Gary