Fermenting volume limit

Hello everyone.
I have a 45 liters fermenter and I would like to maximize my batches volume.
I know it depends on various factors such as style and yeast and I know that I could blow my fermenter in case of overstuffing it and I dont know how big the Krausen could get.
This is what I use for fermenting my beer:

http://img2.mlstatic.com/bombonas-plasticas-branca-de-45-litros-com-tampa_MLB-O-164786326_4988.jpg

For you all:
45 liters = 12 gallons

Any ideas?
Thanks!

You should allow for 30% head space for fermentation and use a blow off tube regardless.

Rafael_Amarins said:

Hello everyone.
I have a 45 liters fermenter and I would like to maximize my batches volume.
I know it depends on various factors such as style and yeast and I know that I could blow my fermenter in case of overstuffing it and I dont know how big the Krausen could get.
This is what I use for fermenting my beer:

http://img2.mlstatic.com/bombonas-plasticas-branca-de-45-litros-com-tampa_MLB-O-164786326_4988.jpg

For you all:
45 liters = 12 gallons

Any ideas?
Thanks!

Click to expand...

My guess would be about 10 gallons to keep from blowing your air lock sky high.

C-Rider said:

My guess would be about 10 gallons to keep from blowing your air lock sky high.

Click to expand...

My "cobrewer" has the same fermenter as I and 10 gallons is just about what we are using nowdays and we had no problems so far with a DIPA and Strong Scotch, this is why I was wondering if I could get closer to top it, maybe get close to 10,5 gallons and not clogging the airlock or blowing the cover up

If you want to maximize the batch size, you could potentially make an 11.5 gallon batch in a 12 gallon fermenter.

Use Fermcap in the fermenter, keep temperatures in check and you should be OK with about 10.5 gallons (make sure you use a blow-off). Save any simple sugars in the recipe for later addition. Once fermentation slows, boil the simple sugars in about a gallon of water, cool and add to fermenter.

Calder said:

If you want to maximize the batch size, you could potentially make an 11.5 gallon batch in a 12 gallon fermenter.

Use Fermcap in the fermenter, keep temperatures in check and you should be OK with about 10.5 gallons (make sure you use a blow-off). Save any simple sugars in the recipe for later addition. Once fermentation slows, boil the simple sugars in about a gallon of water, cool and add to fermenter.

Click to expand...

Nice!
Should I replace the standard airlock for a blow-off for higher output of the Krausen?

Calder said:

If you want to maximize the batch size, you could potentially make an 11.5 gallon batch in a 12 gallon fermenter.

Use Fermcap in the fermenter, keep temperatures in check and you should be OK with about 10.5 gallons (make sure you use a blow-off). Save any simple sugars in the recipe for later addition. Once fermentation slows, boil the simple sugars in about a gallon of water, cool and add to fermenter.

Click to expand...

Exactly what I was thinking....

Rafael_Amarins said:

Nice!
Should I replace the standard airlock for a blow-off for higher output of the Krausen?

Click to expand...

Yes, use a blowoff regardless of headspace, but definitely if you're trying to push the limits of your fermenter. Also, FERMCAP-S is the key word in Calder's post. It's a foam inhibitor (silicone) and will greatly reduce the size of the krausen.

IMO predicting the amount of krausen you will get in a batch is nearly impossible. I have brewed very similar recipes, used the same yeast and amount and had wildly different fermentations.
You could increase your volume until you have a problem.

I suggest that you start EVERY fermentation with a blow off installed. It could save cleaning up a BIG mess.

kh54s10 said:

IMO predicting the amount of krausen you will get in a batch is nearly impossible. I have brewed very similar recipes, used the same yeast and amount and had wildly different fermentations.

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That is very true. I recently split a 10 gal batch into two 6.5 carboys, used the same yeast, same size starters, fermented them side by side and one blew off, the other hardly reached up to the shoulder of the carboy. In that case it was the fermenter that got some trub that blew off, but the moral is the same; always use a blow off until the krausen drops, even if you have gallons of headspace.

Usually I prefer not to use simple sugars at any stage except priming, so I belive I'll be aiming for 10.5 right on the primary fermentation and see what happens then.
Yeah...it will be always a risk.
I'm convincing myself to buy a 50L conical fermenter before september this year, no more upgrades needed for a while. My fermentation temp is done with a dedicated fridge and a temp controler with +-0,5ºC of correction.

Rafael_Amarins said:

I'm convincing myself to buy a 50L conical fermenter before september this year, no more upgrades needed for a while.

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Dooooo iiiiiiit!!