Is a blow off set up necessary?

[Majikcook]

If using a 6.5 glass carboy as a primary, when do you need a blow off system? Only on Big beers? Will a airlock do the job?

 

[Tony]

After my experience of using yeast from a previous batch on a new one and seeing the results of the overly active ferment, I believe for the first 24 hours I will use a blow off set up, then switch to a regular airlock for the rest of the primary ferment.

New yeast pitches, I'll just use an airlock.

 

[user 574]

I'd agree with Tony. Haven't had a problem until I put a batch on the slurry of another batch. That is when I'd consider a blow-off with that much yeast...

 

[lalenny]

I think that if you are going to set the blow-off tube up on your primary fermenter that you should just leave it on there until you are ready to rack to the second. I don't really see a reason to exchange the blow off tube for an airlock in the primary if the tube is already on there. Also, I think that it is only needed if you are re-using yeast from a previous batch. I would suspect a large starter may achieve the same results, but I don't know?

 

[D-brewmeister]

I think that if you are going to set the blow-off tube up on your primary fermenter that you should just leave it on there until you are ready to rack to the second. I don't really see a reason to exchange the blow off tube for an airlock in the primary if the tube is already on there.

I think lenny is right here, no reason to risk something getting into the carboy when switching out a blowoff tube. And since the most brews aren't in primary for more than a week, it realy wouldn't matter much. As long as the end of the tube is submerged in some sanitizer solution or something (which you might need to change a few times if alot of gunk is getting blown off) there is no risk of anything getting into the fermenter through the tube. The only consideration I would see is that the longer all that hop gunk sits on the inside of the tube, the harder it is to clean off.

 

[Majikcook]

Thanks guys, appreciate the input

 

[Janx]

I never use a blowoff tube. Use a big enough fermenter for the batch and you won't have a problem. Blowing off the krausen reduces hoppiness, head retention, etc. It's much better to not have to use one.

 

[Majikcook]

Then I'm messed up Janx... I thought with a 6.5 carboy and a simple airlock would not be enough, and a blow off would be necessary especially when doing a IPA or Stout
My whole reason for wanting plastic pail was because I thought I wouldn't need a blow off....

 

[wwgiese]

If using a 6.5 glass carboy as a primary, when do you need a blow off system? Only on Big beers? Will a airlock do the job?

An airlock is just fine unless you anticipate a problem with the fermenting beer comming out the top. Then the blow off is better. Some people use the blow off and top the carboy to the top. This lets the dead yeast and trub blow off into a bucket and away from your beer. When using this you need to keep dumping and cleaning the drainage bucket and keep some disinfectent in it so you dont get an infection traveling back up into the fermenter.

 

[SwAMi75]

I never use a blowoff tube. Use a big enough fermenter for the batch and you won't have a problem. Blowing off the krausen reduces hoppiness, head retention, etc. It's much better to not have to use one.

How big is "big enough" for a 5 gallon batch of a big beer? My IPA blew the lid off my 7 gallon bucket twice.

I'm wanting to buy a bigger primary for my big beers, but don't know what to get. Since my bucket can't seem to handle the big ones, I'm doubting a 6.5gal carboy would do any better. Plus, I've heard those things are really thin walled.

Sam

 

[rightwingnut]

There's always the 10-gallon "demijohns". I prefer glass for primary and secondary...just feels better using a non-porous material. I doubt anyone's ever blown a carboy...the airlock would pop off before anything.

 

[SwAMi75]

Yeah, that might be the way to go.

Concerning the "thin walled" remark....I'm more concerned about its durability during everyday handling. I'm not too concerned about one blowing during fermentation.

 

[Janx]

I have 14 gallon demijohns for primaries. I brew about 12 gallon batches...at least they fill two 6 gallon carboys full in the secondary and they are more than two corny kegs in the end (kind of a PITA, that).

Now, maybe the "14 gallon" demijohns have more than 14 gallons capacity...I'm sure they do. I've never really measured them. But we only had a blowoff once and that was with a really extraordinarily large batch...probably at least 13 gallons on its own and maybe closer to 14. You could tell it would blow off because it filled the demijohn almost to the narrowest part of the neck.

So, I dunno. It sounds like I have 2 gallons or so of space, and so do you. Mine never blows off but yours does, even though I brew larger batches. I would think the bucket geometry would be optimal, since it doesn't narrow toward the top, and I would think the smaller batch would need less headspace. Maybe it's some other difference in the way we brew? Or maybe I have more space than I think? Or maybe bigger batches are better in terms of blowoff?

As far as the walls of carboys, I find them all very thick...at least the 5 and 6 gallon ones I have. I like my 6's a lot.

The demijohns are of a *much* lower quality of glass. They are frighteningly thin, and that's the biggest drag with them. We broke one a few months back and it really sucked (empty thank goodness, but still $40 gone), and we never noticed how we did it. They have lots of bubbles in the glass and flaws. One of the ones we use now has one of the bubbles sort of halfway broken so you can feel texture from the outside. Scary. It really bugs me about them, and I may move to fermenting in stainless kegs.

For now, we're really conscious of keeping the demijohns in their plastic baskets at all times. We use them only for primaries, so they only get cleaned once a month and then very carefully. They can last years and years if handled carefully (I've seen it happen), but carboys are tougher so we use them for secondaries now.

Anyway, I'm suprised your bucket wasn't big enough. I would have thought 5 gallons in a 7 gallon bucket would be cool. We used to have a big 15 gallon food grade plastic primary, so bigger ones are out there...maybe get a 10 gallon? Or maybe it's something different about the beers we make or the ways we ferment them?

Good luck avoiding blowoffs. It's really nice to not have to worry about it. Cheers!

 

[SwAMi75]

Well, now you've got me thinking, and that's rarely a good thing.....

I'm beginning to think my ferment temps are a tad too high. When I first started in January, I took a temp reading in my pantry closet and got a consistent 69F. This is where I've been doing my primary. Since then, we've had a new heat pump installed, and our outside temps have started to rise.

So going off what little I know, it seems that I started with temps a little on the high side, and they have likely only risen over the past couple of months. In early February I did a porter with an OG of 70, and it put on a hellacious foam but didn't blow over. Then a week ago I did an IPA with an OG of 64 and it blew the lid off twice.

I think my temps might be too high, and my beers are cooking off really quickly. Maybe my solution is to look into some kind of equipment to cool my primary rather than replacing the fermenting vessels themselves.

Does this sound like a reasonable solution?

Sam

 

[Janx]

It's worth a try. You have a cheap option to try to cool them off a bit. Wrap the fermenter in a wet towel/T-shirt/sheet. Keep the shirt/towel dipped into a pan of water so it wicks more water up as it dries. Then point a fan at it. You can lower them temp as much as 10 degrees that way and it doesn't cost anything. Might answer the question as to whether it's the temps or not.

 

[uglygoat]

i got one of those bubles that chipped/mashed on my 6.5 carboy. just a little stress mark, where i accidently let it hit the lip of the sink too hard when rinsing it out... i put some super glue on the outside of it... i don't know if it helped, but it made me feel better, and we use a similar compound on winshields to fill in chips that are of a certian size instead of replacing the entre windshield...

glass glass glass!!!

i've not had a batch overflow yet in my six or six point five jugs. i make five gallon batches. the first batch with the irish ale yeast came really really close to the neck of the bigger carboy, but did not make it's way out. w00t!

 

[SwAMi75]

glass glass glass!!!

i've not had a batch overflow yet in my six or six point five jugs. i make five gallon batches. the first batch with the irish ale yeast came really really close to the neck of the bigger carboy, but did not make it's way out. w00t!

It was the Wyeast British ale that went nuts on this latest batch.

Thanks for the advice fellas, I'm got some 'spearmentin' to do!

Sam

 

[Brewman]

I love my blow off........ I can squeeze a couple of extra beers in.....

 

[Janx]

...and then they blow out the blowoff with about 30% of the hop character...

Without a blowoff you get to keep the extra beers you put in there. It really is better to not have one if you can at all manage it (ie if your fermenter is large enough).

 

[user 574]

Well last night I brewed a batch and dropped it on the slurry after racking the other one. Fully expected another "explosion" like my previous experience so I rigged up the following half-baked blowoff setup using a racking cane, trimmed bottom airlock, racking tube and a bucket with sanitizer to catch it. The goofy string is to offset the cane trying to pull it off to the right. Bummer is it never got that vigorous of a ferment that warranted it (yet) but don't think it will. Kind of nice to know if it would work...

She's bubbling like crazy but nothing spewing out the top of the fermenter. After doing this setup though it really just seems like a "big air-lock". I've read Janx's comment from others as well about a blowoff can waste beer but what is the difference between an airlock and blow-off if neither get an aggressive enough ferment to push through? I guess the airlock can try and keep it in there but if its big enough; boom/mess just like last time which could get infection if your not around to clean it up.

 

[Janx]

What you have is just a big airlock, as is any blowoff tube, but it's a bit easier to clean up than letting it blow out all over the place.

To clarify, I recommend using a large enough fermenter that you need no blowoff tube. The biggest reason besides the mess is that you lose a lot of hop character through the blowoff.

 

[Janx]

I forgot to mention this stuff:
http://www.morebeer.com/product.html?product_id=15464

It's been around forever, but I've never tried it.

Another thought is that maybe it's the yeast strain that's causing the blowoff, and I've just been lucky. I've got a White Labs Wit starter going and the head stacked up at least 3 times as high as the liquid. Very persistent bubbles. So, it'll be interesting to see if it climbs out of the fermenter when I pitch it.

 

[brelic]

...and then they blow out the blowoff with about 30% of the hop character...

Without a blowoff you get to keep the extra beers you put in there. It really is better to not have one if you can at all manage it (ie if your fermenter is large enough).

I realize this thread is about 4 years old now.

In any case, along the lines of what Janx is saying about losing the hop character through a blow off, is it then in a sense better to use an open fermentation (primary bucket with a lid that does not create an airtight lock)? That's what I've been using ever since I started AG batches last year, and I've managed some pretty nice beers with it (all while perfecting the techniques and accepting the mistakes that come with learning).

So, my question is, is there a significant difference between an open fermentation like I"m doing, a closed fermentation without a blow off tube (just an airlock, I suppose), and a closed fermentation with a blow off tube?

 

[Bruin]

Had my first blow off today using Wyeast Irish ale yeast for a stout kit. 6 gallon Better Bottle. Less than 22 hours into fermentation w/65 deg air temp. Changed gunked up dry airlock out with blow tube. Man that thing is bubbling in my sanitizer bottle like somebody blowing through a straw. Impressive!