Air lock drawing in fluids

I am having a problem with my air lock, my beer has been in the primary fermenter for 10 days now, I am using a 14.5 gallon more beer conical. The fermentation has stopped, and I noticed yesterday that the water in the air lock was low so I tried adding some Vodka, I filled it to the line and left it alone, I noticed today that it was low again, so this time I added one step solution (thinking the vodka evaporated quickly). When I added the one step solution it was immediately sucked into the fermenter and the level is low again. What should I do about this? I am assuming that the pressure is lower in the fermenter and that is why the fluid is being sucked back in? Should I tape the top of the air lock since it has holes in it? I am planning on adding bourbon and wood chips and letting the beer sit for a few more weeks since it's a bourbon barrel porter and I don't want the beer oxidizing if it is sucking in outside air?

Thanks, Jeff

Welcome to HBT jeff. The most common reason is when you attempt to cold crash or if the temps were raised during ferment and now the temps have dropped in the fermentor and creating "suck back" I avoid filling the airlock to the fill line. Another cause could be pressing on the fermentor lid or sides and evacuating the internal pressure. Keep some vodka in the air lock and you should be fine. I wouldn't tape the holes it defeats the purpose of the lock.

Thanks for the reply, so I should not seal the air lock now that fermentation is complete? I also have an S - shaped airlock that I am not using that has a sealed cap on it and I thought about replacing the current air lock with this? My main concern at this time is that the air lock may be drawing in outside air since the fluid level is low and I can't keep it filled?

Thanks, Jeff

sure its not cracked?
id switch to another airlock if you have one.

I don't see any cracks, and as soon as I added the one step solution I could see it getting sucked into the fermenter.

Is the temperature where the fermenter is located stable? Good idea on changing out the airlock. That will at least tell you if the other one is faulty.

What are you seeing as far as temperature changes? This almost always comes from a temperature drop. I've never used an S lock but it would have to have a way of allowing co2 gasses to escape the fermenter so there has to be a hole somewhere above the liquid area.

I like oldstyles suggestion to change to another airlock if you have it. I have a box of them and never had trouble, but you never know.

I got the s locks for exactly this reason, and only put a little bit of solution in them. It just made sense to me. Ive only done 3 batches so far and actually am having very, very good results using just the blow off tube in this one batch. It seems more sanitary to me. I think in the future I will just use a bung and thinner style bottling tube. The long tube should eliminate any chance of sucking water back in right? And isn't that big of a temperature change bad for fermentation, anyways??

I will change out the air lock and see what happens, I didn't think leaking was a problem since I saw the fluid being drawn into the fermenter. I will say that the temp has dropped several degrees as we are seeing very cold temps recently and my basement is cooler than usual. I put a space heater down there, but I am trying to adjust it properly since recently I noticed that the fermenter got warmer than I planned (about 72 to 73 degrees), and then dropped into the low 60's when I moved the heater a little further away.

jefft321 said:

I noticed that the fermenter got warmer than I planned (about 72 to 73 degrees), and then dropped into the low 60's when I moved the heater a little further away.

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That is enough of a cooling temp change to cause some minor suck back.

Dang man, im sure you'll be okay. I would think any solution getting sucked into your fermenter wouldn't be a good thing. Think of this as an experimental batch, you'll know exactly how to control this stuff next time o round. The best thing about beer is, you can always make more.

I agree it is most likely a temperature drop issue. That will cause a pressure differential that would draw in.