Blow offs - what is the cause and . . .

[Grinder12000]

Blow offs - what is the cause and can a person predict them?

I always try to predict how a brew will react. I brewed an IPA yesterday and man it's looking like it'll have a blow off even with a 65 degree ferment.

Got me thinking - what is the cause.

I've had 37ish brews and perhaps 5 or 6 blow offs (some pretty close). Some I think will have a blow off and don't and others are surprises.

 

[Brooklyn-Brewtality]

certain yeast strains are more likely (hefeweizens especially).

but often it is random chance.

 

[corvax13]

I am not sure if there is any reliable way of predicting a blow off - it depends on the kind of yeast used, how many yeast were present, variables in temperature, variables in different beer styles, ingredients... probably even if the yeast are in the mood to have a blow-off or not.

I can tell you one thing though, there is a good way of predicting how not to have one, and that is by using a blow-off tube.

 

[tdavisii]

I always do a search on HBT of the yeast im going to use if I havent used it before....I just brewed a hefe with 3068...Thank god i did some research because within four hours i needed a blow off.

 

[cactusgarrett]

I would consider a large healthy pitch to be one of the main "causes". Kinda goes without saying, too, but how much headspace you leave in your primary pretty much seals your fate.

 

[PseudoChef]

Protein in the wort. More protein (i.e., wheat based malts) and there is more krausen.

 

[Grinder12000]

I'm always watching the 1st 24 hours. hefeweizens you say? - my next brew is a hefeweizens so I'll be prepated.

I've never had a mess with a blow off. Always ready!

 

[Flic]

After about 15 AG brews, I just had my first blowoff yesterday with an Imperial Russian Stout. Came in at 1.092 OG and I added 4 packs of Wyeast London Ale III (my 1st attempt at a starter went bad). I brewed 4 gallons and is in a 6.5g plastic bucket. I wasn't sure I'd get a blowoff with 2.5 g headspace but I rigged one up anyway. Sure enough, after 24hrs it was quite a sight to see.......

 

[flyangler18]

Protein in the wort. More protein (i.e., wheat based malts) and there is more krausen.

You beat me to it, Protein Nerd.

Wort gravity, yeast strain, cell count, fermentation temperature, etc. are also contributing factors.

 

[Grizzlybrew]

My vote would go to pitching rates - look at commercial set-ups. What microbrewery doesn't have yeast blowing off? I would be disappointed if I didn't get one. Plus, I love the sound of a huge gurgle of blow-off in the jug. Although, I think I have lost 1/4 gal of my "last minute marzen" to the jug and it's at 58 deg!

(1) Blow-off tube the primary always and (2) airlock the secondary is my approach.

 

[Rick500]

I was gonna say frisky yeast, but protein sounds likely.