Why Switch To An Airlock?

[AZCoolerBrewer]

Re-hydrated my US-05 this time instead of sprinkling the dry stuff. Really happy with the nice active ferment that I am having. My experience so far with 05 is that it is the tortoise where the other Fermentis yeast I've used S-04 is the hare. The problem is I waited the prescribed 3 days. My krausen dropped a bit and seemed stable and I switched to three piece airlocks. The next morning, my airlock is fouled with krausen and I have to monitor it all day to make sure my airlock doesn't boil over. Is there any good reason that I should switch to the airlocks or does the blow off tube set up do exactly the same thing except with less need to worry? I saw the setup at Lumberyard in Flagstaff AZ and it looks like it is basically a big blow off tube.

 

[lumpher]

You don't want to keep a blowoff tube in there the whole ferm time. Eventually it will cool off and suck the blowoff back into the beer.

 

[MattHollingsworth]

I've never seen a blowoff tube suck back into the beer after all these years of brewing. Might happen if you leave it on and then cold crash the beer. Never tried that myself. These days I don't have to use one very often as I generally ferment 25-27 liters in a 34 liter demijohn. I had WLP029 German Ale/Kolsch blowoff just recently, though. I just leave the blowoff on there until the head has clearly dropped. Sounds like you did that and it came back. You can safely just leave it on there for a few more days with no worries, IMO.

 

[Redlantern]

When I run a blow off tube, the end of the blow off sits less than 1/4 inch in the starsan. No way this system can suck liquid up 20+ inches of a 3/4" tube and into the fermenter.

 

[Nagorg]

I've had my blow-off tube suck StarSan back into my beer. But, it WAS only because I left it setup while doing a cold crash. That's a mistake you only make once!

Since then I regularly leave it until either dry hopping or cold crashing which I dont always do. Maybe I'm too lazy... But this hasn't been an issue at all.

 

[beergolf]

A blow off tube is just a big airlock. Suck back is only an issue if you cold crash. I often leave the blow tube the whole time during fermentation and not switch to a tegular airlock.