6 gallon better bottle fermentation capacity

Hello fellow brewers.

I’m a new brewer here, and have a silly little question.  What would you say a max fermentation capacity of a 6 gal Better Bottle would be?  In researching recipes I have seen recommended top offs of 5.25 gal or higher.  Wondering if I am ok still.

Thanks in advance for your insight.

At 5.25 gallons you would have adequate head space with a blow off tube but you might lose a bit of yeast as it blows out.  Even with only 5 gallons I’d still recommend a blow off tube.

Remember that at the bottle tapers at the top reducing available space for krausen.

So would you say that is pretty much the max?

Yup:)

Brilliant!

Thanks.

I put 5.25-5.5 gallons in all the time. I always use a blowoff and need it about half the time.

No more than 5.2513543234321.

5.5 gallon in mine with a blowoff tube.  Some blow off more than others.  I also use Fermcap-S at the start of my boil so I don’t know if any of that carries over.

The orange carboy caps and 1/2" vinyl tubing making a great blowoff setup.

I use the orange caps as well but attach the blow off to the smaller end and use 3/8". The tube will sometime get constipated and I won’t here any bubbles. It’s like the fat kid from willy wonka. I do it this way since I stick a thermowell in the later port.

I also use large hose clamps with a wing nut to tighten seal it up well.

A number 10 drilled stopper will work for a blow off too. The 3/8" tube will sometimes get clogged like Steve said.  A few years ago I bought a drilled No. 10 with a 1/2" hole which works better.  Northern Brewer sells it as a Blowoff Assembly for PET  Fermenters.  If you use StarSan as a sanitizer, the stopper gets a little slick and likes to pop out until it dries.

Without the cap I believe 1" tubing will fit snug in the opening as well

For a regular carboy, yes, but not for a BB. They have an extra wide (1.75 in) opening, which is much larger than a standard glass carboy.

Thanks, it’s been awhile since I used a carboy:)