Is a Blow-off Tube Actually Necessary?

[DavidDetroit]

I have 37% headspace in the fermenter. That is almost three gallons-worth (11 liters) of headspace for a five gallon (19 liter) batch in my fermenter. I have never even come close to needing a blow-off tube despite high ABV beers (up to 13%) or styles. Is there anyone else horrified at seeing their hard work spill into a container and then thrown away?

Is it the use of large starters in the liter range? That would still leave over 2.5 gallons (10 liters) of head space though.
Is it just fun to see the beer churn up out of the vessel?

The practice of blow-off tubes has just never made much sense.
EDIT: error in original post corrected to 37% headspace in fermenter

 

[Chippy_Tea]

I don't think they are used as much in beer brewing as in wine making (i always use one) i know some beer brewers here do use them.

,

 

[DavidDetroit]

I don't think they are used as much in beer brewing as in wine making (i always use one) i know some beer brewers here do use them.

Not that I technically know the "how often" but my perception is they are prevalent, at least on the sister-site.
I'm mostly interested in exactly why one is necessary for beer. I'm quite open to learning. Possibly, the sister-site is the better source and I may try that if this doesn't pan out.
I'm not exactly getting a lot of replies. I should offer a twenty pound note to Tesco's or something.

 

[Moe]

I have a 30l SS Brewbucket and brew 23 batches. I use a blow off as it won’t fit in my ferm fridge with an airlock sticking out of the top.

90% of brews are fine, so the blow offs not doing anything an airlock wouldn’t, but when I use Verdant yeast it comes pouring down the blow off and into the jar, so saves the cleanup as the yeast just goes into the jar

 

[foxy]

I use a blow off tube, before that just used cling wrap. You have to have something to discharge the co2.

 

[DavidDetroit]

Verdant

So it's the yeast, then, for you. What size of a starter do you use? 7 liters available but that could change with the starter size, I'm guessing.

 

[DavidDetroit]

I use a blow off tube, before that just used cling wrap. You have to have something to discharge the co2.

So you're not losing beer, basically?
If I did get a significant amount of lost product, I'm either running to the store to get a bigger fermenter or I'm reducing my batch size.

 

[Moe]

So it's the yeast, then, for you. What size of a starter do you use? 7 liters available but that could change with the starter size, I'm guessing.

I don’t make starters, it’s dried yeast so I just sprinkle the packet in.

It’s a lovely yeast but goes off like a volcano

 

[DavidDetroit]

I don’t make starters, it’s dried yeast so I just sprinkle the packet in.

I would not have guessed "dry." I only use dry too so I considered that might be a possible reason for my never needing a tube. I'll check out the Verdant. How many packs do you use?

 

[Moe]

I would not have guessed "dry." I only use dry too so I considered that might be a possible reason for my never needing a tube. I'll check out the Verdant. How many packs do you use?

Only 1. This is last year when I used CML Five yeast, this is an active one too.

Its not that you have to use a blow off tube, it just stops you having to clean up and change an airlock out during fermentation.

 

[DavidDetroit]

That's some explosive reaction.
Could an interaction with a large amount of hops be the cause?
I don't use a large amount of hops.

Only 1. This is last year when I used CML Five yeast, this is an active one too.

 

[foxy]

So you're not losing beer, basically?
If I did get a significant amount of lost product, I'm either running to the store to get a bigger fermenter or I'm reducing my batch size.

Never lost beer yet, my fermenters are around 66% to 33% head space. I have gas posts on my fermenter and a wine carafe with sanitised water in it. Because the discharge hole is so small there is a small amount of pressure in the head space. The pressure keeps the foam at a manageable level, I have also noticed the more water in the carafe the pressure increases. The professional brewers cap their pressure at around 1P above the target FG, they are the ones who really complain about any foam coming out of the blow off tube, to them that is losing money.
When I say pressure, the amount wouldn't be measurable on a standard pressure gauge.
What is the purpose of "Capping" fermentation - ProBrewer Discussion Board

 

[Hazelwood Brewery]

I only ever have this issue when fermenting imperial stouts with big starters. Huge quantities of food for a large army of yeast leads to massive fermentation. Ordinary beers with smaller yeast additions - no problem.

 

[DavidDetroit]

Never lost beer yet, my fermenters are around 66% to 33%

Those percentages made me recheck my own. Mine is actually 37% headspace, not 27%.
That's a real nice setup you have.
I'm pretty bare-bones with it all. Beer's good and the kinds I like hide errors.

 

[DavidDetroit]

I only ever have this issue when fermenting imperial stouts with big starters.

Would it behoove you to use a wider ratio of headspace to beer or it's just not worth considering?
I get away with two packs of dry for my 12% ABV stouts. I've thought about making them a cream, rehydrating or something like that.
One time, I went downstairs to grab a scale while brewing on the stove and it foamed. I lost about a cup of beer and, boy, was I bummed. Just me.

 

[Hazelwood Brewery]

Would it behoove you to use a wider ratio of headspace to beer or it's just not worth considering?
I get away with two packs of dry for my 12% ABV stouts. I've thought about making them a cream, rehydrating or something like that.
One time, I went downstairs to grab a scale while brewing on the stove and it foamed. I lost about a cup of beer and, boy, was I bummed. Just me.

Not worth it for me, I don’t often make such big beers / starters. I didn’t loose any beer at all, just a little krausen that escaped through the tube.

 

[Poochops]

I only ever have this issue when fermenting imperial stouts with big starters. Huge quantities of food for a large army of yeast leads to massive fermentation. Ordinary beers with smaller yeast additions - no problem.

Yep me too, did an impy once just 12 litres in a 35 litre bucket, the brewfridge looked like a scene out of quatermass it took me about an hour to clean it out and another to transfer out and clean the fermenter. Tasted bloody great though

 

[scomet]

I over-pitch rehydrated Nottingham in a most of my beers, I used to get lots of volcanic yeast eruptions but not anymore, imho the better the process the better the beer and incidentally the better behaved your yeast is. I can peg my krausen top 95% of the time to 10mm, sorry thats 1/2” :-}

 

[DavidDetroit]

1/2”

that was funny. I appreciate it though.

 

[DavidDetroit]

For real, I was taught we were going metric. I learned it. I was totally ready and understood the system. Then it went away--poof. Don't know what went awry.