Beer Forum

Oops, I mean, blow-off techniques.

Something's been bothering me since I attached a blow off tube to my carboy last week. First time blower, long time blowee, BTW.
So, I put the outgoing tube into a small bucket of iodophor solution, submerged a couple inches, and clamped off to the bucket.

As expected, I had a "robust" ferementation and quite a bit of kraussen was ejected into the bucket on the first day. So the question is, once you've mixed kraussen foam in with the sanitizer, for how long does it remain sanitary? Is it immediately a vector for infection...does it take a while to decrease the sanitizer acidity below sanitary levels? I changed the hose out on day three for a sanitized airlock, and I crossed my fingers that I wouldn't have a second high kraussen. Now I'm at day 9 and it looks like I'm in the clear.

I've seen advice to just change out the sanitizer water when that happens, but what bothers me about that is that it does nothing to adress the schmegged out interior of the hose. Also, I've heard that using a blow off tube subjects the fermenter to more back pressure than you'd get with an airlock, and that tends to keep more CO2 in solution, which I imagine changes the character of the ferment.

Am I going about this right?

It doesn't matter if it's sanitary, as long as it isn't getting sucked back up. Suck back is more likely to happen if you have big temp swings. You could put the end of the blowoff in a jar of piss and probably have no issues with the finished beer. There generally will be more back pressure because most people are going to put the blow off under a greater depth of water than what it will push through to go through an airlock. Unless you are putting it at the bottom of a 5 gal bucket, you shouldn't have an issue.

Would you advise to keep the blow off tube through the duration of the ferementation, or should it be swapped at some point for an airlock?

Changing the sanitizing water kind of worries me, because you're allowing an oxygen pathway into the hose at that point. If it's already coated with sticky sugars, I just imagine it being a flashpoint for infection. I suppose the O2 would be pushed out again in short order though.

Bucketfull of piss eh? That could save me some $ on sanitizer.

If you change the bucket during active fermentation there is still co2 being produced so that will keep the oxygen out. I use foil to cover the opening of the carboy for the initial part of fermentation because of that. Then throw on an air lock until it's done.

Thanks guys...Looks like I have nothing to worry about.

Try using ferm-cap S foam inhibitor for this issue. Less work, less chance of any problems, and the big one is that you won't lose any precious yeast which is needed for your fermentation. I really don't understand why people continue to still use blow-off hoses if this product is available to the masses... I guess you just all like extra work!

Having a spare bucket is always handy. Get your 2nd bucket ready & just swap em. You'll already be blowing into your 2nd bucket while you're cleaning the 1st one. But it really isn't all that big of a deal as mentioned before. I tend to swap them out 2-3x a day for the first couple days & slowly taper off as fermentation activity gets under control. I switch to an airlock when the blowoff tube isn't needed anymore - when the foam stops reaching the top. Giving it a slight swirl when you change buckets doesn't hurt either. As one learns by top cropping, that yeast suspended in the foam is some of the best available.

I found I could force a 1/2 inch plastic elbow through the drilled stopper and attach a 1/2 inch blowoff hose. This greatly reduced the back pressure in the fermenter. To clean up I soak the assembly in pbw and rinse. I replace the scuzzy blowoff water daily until fermentation subsides and replace the blowoff rig with an airlock.