blow off tube vs airloc

[yrud12b]

On my first brewing, I was able to use the air-lock without trouble on a 6.5 gallon glass carboy. I did a second brewing yesterday after bottling the first batch. My first was a red ale, this was a brown ale extract kit. This morning the air-lock was clogged with hop debris and bubbling around the seal. I had to remove the air-lock and replace with a blow-off hose into a bucket of star-san solution. (That was after I cleared all the krausen off my face and took pictures of the debris all over the ceiling). What was different about this brewing that caused the large krausen and need for a blow-off tube? Was it the type of kit, the extra hop additions, the temperature, type of yeast, or that I did a better job aerating it before I pitched the yeast? Trying to predict what to use next time so I don't have such a mess. I have read posts about using air-lock vs blow-off and will do a blow-off for at least the first 3 -4 days next time, but why the difference? Thanks!

 

[unionrdr]

First of all,every brew is different. Even if it's the same kind of beer,or the same kit. also,getting the wort temp down to mid-60's will help slow things down a bit so that a blow off may rarely be needed. That's my experience anyway,liquid with a starter or dry rehydrated. The warmer the wort is,the more likely it is to need a blow off. Or if you pitch a ton of yeast.

 

[JimRausch]

Well, the Q of how vigorous a fermentation depends on 3 things I can think of:
1. The OG, ie. more fermentables could lead to a bigger blow.
2. Yeast strain- some are beasts, others more civilized.
3. Most important- fermentation temperature. Higher temps will definitely give you a bigger fermentation reaction.
So, if #1 and 2 are same or close, I would bet your temp. on the 2nd batch is higher than the 1st. Do your best to keep her cool, especially in the 1st 24 hours.
Ok, I thought of a 4th factor- head space. If you don't have enough headspace to allow for expansion, then it has to go somewhere, right?

 

[bajaedition]

I think every brewer who has been doing it a while will tell you about the time he had a brew do that
Sometimes it happens
Airlocks work best when there is plenty of space below them and the fermentation is average. they are a good invention. I used them for years and switched to blow off tubes, I now use Speidel fermentors and have gone back to airlocks, but then the airlock the Speidels use is huge.
I think that is the issue, those airlocks we use normally are a little small for the potential in a 5 gallon batch of beer.

Good luck

 

[yrud12b]

We were in a bit of a hurry to get it in the carboy before kick-off yesterday, so the temp was probably a little warm. It felt room temperature to the touch... I guess I will TEST it next time to be sure before we pitch. Now I'm really wishing I hadn't watched that game and will be wishing again tonight while I'm cleaning the ceiling. The fermenter temp was at 74 when I put the blow off tube in today. I try to keep it at 68 for the two weeks. Thanks for the advice.

 

[yrud12b]

Okay, now that I've started the clean up, I'm wondering if I blew out too much to finish the fermentation. When all of that krausen plastered my ceiling, did it contain too much of the yeast to see good action in the fermenter over the next few days. Do I try to pitch more yeast? Is there any way to know how much blew out if it happened 15 hours after the original pitch? Currently it's fermenting back under an airlock and bubbling every 20 - 30 seconds. The inside tapered top of the carboy is covered with plastered hops, so it's hard to see whats happening on the surface. The wort is churning a little, but not near like my last brew at this stage.
Thanks for any further help. -Jeremy

 

[unionrdr]

It sounds like it's past initial fermentation. It'll then slowly,uneventfully creep down to FG.

 

[kombat]

First of all,every brew is different. Even if it's the same kind of beer,or the same kit. also,getting the wort temp down to mid-60's will help slow things down a bit so that a blow off may rarely be needed. That's my experience anyway,liquid with a starter or dry rehydrated. The warmer the wort is,the more likely it is to need a blow off. Or if you pitch a ton of yeast.

+1

That's pretty much exactly what I was going to say. To be honest, I rarely use a blowoff tube. I'm simply very attentive regarding my fermentation temperatures. I place my fermenters in a plastic laundry tub filled with water, and covered with a wet t-shirt. I monitor the temperature of that water bath at least twice a day during those crucial first 2-3 days of fermentation, adding ice as needed to keep it between 60-65° F. I've had a couple "bigger" beers push a little krausen through the airlock, but nothing so vigorous that it required a blowoff tube.

 

[40watt]

For safety sake, I use a tube during initial stages of fermentation, and then switch to an airlock for the long haul.

 

[Opiate42]

A question I've had but can't seem to find an answer for:

What happens if you leave the blow off tube in for longer than a few days? I got ridiculously busy the week after a brew day Sunday and forgot to swap to the airlock after the krausen had collapsed. Didn't get to it until 6 days later on the following Saturday.

Any ideas on what kind of effects this may have? If any?

FYI: It's a 1 gallong batch of a wheat beer, krausen was very active and went right up the blowoff tube into the sanitizer bucket. *so now of course I'm having a hell of a time cleaning out the tube lol

 

[40watt]

I have left a tube in for months with no adverse effects.
Just as long as the other end stays submerged in viable sanitizer.

 

[JimRausch]

Nothing bad will happen if you leave the blowoff on and skip the airlock completely. Lots of folks use a blowoff for the whole process.
And I don't have a magic technique for cleaning the cruddy tube. A long soak in PBW/BBrite/Oxyclean works OK. Would be nice to have a really small bottle brush though.
Hmm- That last comment reminds me of the days when I played the trombone. There is a long flexible tubing with a small brush on the end designed for cleaning the slide. I'll have to see if I can find my old one and give it a try.

 

[glenn514]

I look at a blowoff tube as really, REALLY, R-E-A-L-L-Y cheap insurance! I've brewed some recipes multiple times, and each fermentation seems to have a mind of its own. Using a blowoff for the first 48 hours of fermentation prevents most problems that could occur. Following that initial vigorous fermentation, I usually swap out the blowoff with a regular airlock.

glenn514

 

[unionrdr]

I bought a 66" long,3/8"diameter brush from keg connection,something like that. some 3/8" hoses it fits,in others it gets hung up. Sizes seem to differ a bit from one brand to another.