Why is a carboy(secondary fermenter) smaller than the primary?

I dont understand why the carboy is exactly 5 gallons while its seems that most brewers use larger primary fermenters.


I want to get some carboys going with brews and ciders , but I dont mind having sediment in my beer, therefore primary fermentation is fine with me. My question is can I use a standard 5 gallon carboy, for a 5 gallon brew. thanks, everyone here has been very helpful.

You need the extra gallon of room in the primary fermenter because otherwise you'll have a massive amount of foam spewing out of it. You only need five gallons for the secondary because when you transfer the beer into it, fermentation should be pretty much complete, and there's no more risk of foam spilling over.

thank you, one other question, is it ok not to have a tube to get rid of the foam, instead having an airlock or bubbler?

BoxerDog said:

thank you, one other question, is it ok not to have a tube to get rid of the foam, instead having an airlock or bubbler?

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Yes, MOST of the time. Every once in a while, especially with some yeast or bigger beers, you get more massive fermentation. For those instances, having the blowoff tube handy is really nice.

Typically, I start with an airlock and only go to a blowoff when things start looking bad for the airlock

I'm all about the 1.25" blow off tube. It will not clog and all that crazy stuff. Then after 5-6 days when fermentation slows I put the air lock on and wait it out. Getting rid of the foam is a good thing a lot of the time because it can blow off the crud that makes the hang over worse.

-67-

67coupe390 said:

I'm all about the 1.25" blow off tube. It will not clog and all that crazy stuff. Then after 5-6 days when fermentation slows I put the air lock on and wait it out. Getting rid of the foam is a good thing a lot of the time because it can blow off the crud that makes the hang over worse.

-67-

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Me too. You put in the blow off tube and there are less worries for the first several days.

Definately spend the few bucks for some blow-off tubing. Beats cleaning up a mess.