What are the disadvantages of using a blow off tube?

[pjj2ba]

+1 on the Fermcap.

I've used it for two batches so far and am REALLY pleased! No blow off needed, only about 1" of krausen. Prior to this I was getting some pretty vigourous blow offs and losing a couple of pints of beer in the process. Now I can fill my carboys up pretty high and not lose any beer. I'm going to tap the first batch this weekend and I'm curious to see if there is any difference in the clarity.

Our local microbrewery uses it in the boil too. The brewer likes to push the limits of his boil kettle and he said that using the Fermcap has made a big difference although they still have to watch carefully for boilovers, expecially on the bigger beers (more initial protein)

What I'd like to know and haven't read anywhere is if you add it to the boil, do you need to add more when it goes into the fermenter? Does it get trapped in the trub in the boil kettle?

 

[Funkenjaeger]

I love using it in the boil. Before I got my keggle set up, I was using a 30qt turkey fryer pot. One batch had maybe 2 inches of headspace, and I got it going without even a threat of boilover, without having to spray it or go crazy controlling the burner, etc.

It's also indispensible for boiling starter wort. Here's close to 900mL in a 1L flask:

It'll "bubble over" occasionally, if you're boiling it vigorously, meaning you'll get a small surge of those big bubbles like in the picture, but that's a VERY small amount of liquid and doesn't make a mess - no burning smell, and a quick wipe with a wet paper towel cleans it up after - there's really no threat of "foam over" like you'd get without foam control.

What I'd like to know and haven't read anywhere is if you add it to the boil, do you need to add more when it goes into the fermenter? Does it get trapped in the trub in the boil kettle?

When I have used it in the boil, I find I still need to add some in the fermenter. It almost seems like the additions to kettle and fermenter are separate - not sure if the stuff gets boiled off, or stuck in the cold break, or what. I don't really have much of a system, per se, I sort of add it as needed - I add maybe 5-10 drops to the kettle and then maybe 5-10 to the fermenter and then add a couple more drops if the krausen starts to climb too much.

 

[TexLaw]

I also find that I need to add Fermcap S to the fermenter, as well as the boil. I've only used it in the boil once, but I did look like a boilover was more possible toward the end of the boil. Since it's just a teaspoon for five gallons, I went ahead and tossed another teaspoon into the primary before adding the wort.


TL

 

[abracadabra]

According to John Palmer or Charlie Papazian, I forget which, having a blow off makes better beer.

Also if the bottle that your blow off tube goes into is sanitary and has sanitary water it's perfect for harvesting yeast.

 

[balto charlie]

According to John Palmer or Charlie Papazian, I forget which, having a blow off makes better beer.

I remember Papazian said to blow off to get rid of some nasty oils??? or something like that. Looks nasty to boot. I blow off or use a larger fermentor.

 

[Funkenjaeger]

Also if the bottle that your blow off tube goes into is sanitary and has sanitary water it's perfect for harvesting yeast.

Sanitizer typically becomes ineffective when it gets dirty. After several days of krausen being blasted into a bottle of sanitizer, and the bottle itself being open to the air, I think it's quite safe to say that it's not going to be very sanitary any more - if it is, you probably also killed all the yeast that went into it. You could seal the blowoff bottle, use plain water instead of sanitizer (or nothing at all) and stick an airlock in it, in which case I think you're talking about a burton union...

But I do NOT think it is okay to go harvesting yeast from a bottle of sanitizer, yeast, and krausen that's been sitting open for several days.

 

[FlyGuy]

One other very minor annoyance with blow-off tubes occurs if you use a shirt or box with a hole in the top to cover your carboy (say for cooling or to protect from light). It can be a pain to remove these covers because you need to feed the hose through the hole in the top. If you have tried this, you know what I mean.

I use rigid blow-off tubes made from PVC, which I like much better than plain hose, but they can be a PITA with a cover.

 

[Homebrewtruth]

There are a few disadvantages to using a blow-off tube. It is used because you don't feel your head space is large enough to accommodate high krausen. The krausen is then piped off instead of just settling back down into the beer. Not only do you lose beer, but you lose a lot of the important proteins in the krausen that are head forming. I ferment 23 litre batches in 40 litre containers. I have healthy, vigorous ferments by hydrating dry yeast in water first before pitching (thus making my yeast much more viable than if I pitched straight into wort) and have never had to use a blow-off tube.

 

[mjohnson]

lol. The thread... its... ALIVE!!!

 

[kh54s10]

There are a few disadvantages to using a blow-off tube. It is used because you don't feel your head space is large enough to accommodate high krausen. The krausen is then piped off instead of just settling back down into the beer. Not only do you loose beer, but you lose a lot of the important proteins in the krausen that are head forming. I ferment 23 litre batches in 40 litre containers. I have healthy, vigorous ferments by hydrating dry yeast in water first before pitching (thus making my yeast much more viable than if I pitched straight into wort) and have never had to use a blow-off tube.

Well, you have a very unusual system having almost 50% headspace. Most home brewers are doing 5 gallon batches in one of 3 fermenters. A 6.5 gallon carboy, a 6 gallon Better Bottle or a bucket that is about 7 gallons.

Most blow offs are not so great that you will loose too much beer so the loss of beer or proteins is of no great concern.

For those using Fermcap-s, don't get too complacent. I have had 2 batches that had some blow off even with the Fermcap.

I have also heard warnings about sucking back a couple of gallons of liquid from the catch vessel. My question is why? You only need enough liquid to keep the hose end underwater. I use only about a cup of Starsan solution.

 

[phoenixs4r]

Who's got the grave digger thread image? Holy moly.

 

[sarsnavy05]

Thanks for the thread resurrection! I was passively wondering the same thing, but didn't care enough about it enough to search for it!