Fermenter size ratio to wort quantity

[MarcGuay]

Hi folks,

Can I use a 6gal primary fermenting bucket for a small 2.5gal batch or does the amount of headspace for air make a difference?

Thank you
Marc

 

[kev211]

The short answer. Yes you could.

But you dont want to. That extra headspace is a primo place for an infection to begin. I would either split it into 2- 1 gal fermentors or do a 5 gal batch

 

[MarcGuay]

Ideal fermenter size would be ~3gals? Could I put water in a sealed, sanitized container inside the fermenter to bring the top of the wort closer to the lid?

 

[kev211]

Ideal fermenter size would be ~3gals? Could I put water in a sealed, sanitized container inside the fermenter to bring the top of the wort closer to the lid?

Or you could get a 3 gal fermentor. Forgot they made those haha. In theory you could displace the wort with a sealed container although it seems like another way to infect it. My general practice is, the fewer things I can put in the wort/beer the better

Just curious, why a 2.5 gal batch and not 1 or 5?

 

[MarcGuay]

I have a 3gal boiling pot and thought it would be perfect to divide a 5gal half-boil extract recipe in half. (First time making beer).

Just double-checked the fermenter the homebrew store gave me and it's 32L/8.4gal... Pretty big...

 

[kev211]

Keep in mind, to do a 2.5 gal batch you're gonna have to boil off prob .5 gals. Even if you started with a 2.5 gal boil that still doesnt leave you much room for boiling action/no boil overs. If it were me I would either get a bigger kettle or do 1 gal batches

 

[TallDan]

I'd say you'll be fine with a 2.5G batch in a 6G fermenter. If you want to cut down the head space some, go get a 5G bucket instead. 5G food grade buckets are cheap and easily available at the local home improvement stores here, I'd imagine the same is true in Montreal.

 

[MarcGuay]

I've done a bit of googling (should have done it before asking) and it seems like most people say that headspace isn't important for primary fermentation because the CO2 will fill it up. Since I only plan on doing a 2 week primary, no secondary and no dry-hopping, I think I'll just give it a shot in my too-big fermenter and see how it goes.

 

[petrolSpice]

I think it would work just fine. The concern is an infection starting on the sidewalls of the headspace before fermentation starts. Just sanitize very very well and it should be good. Once it ferments CO2 will fill up that space in no time.

 

[MarcGuay]

Keep in mind, to do a 2.5 gal batch you're gonna have to boil off prob .5 gals. Even if you started with a 2.5 gal boil that still doesnt leave you much room for boiling action/no boil overs. If it were me I would either get a bigger kettle or do 1 gal batches

I'm following "How to brew" and he says for a 5gal batch to start with 3gals in the pot so I figured I could start with 1.5 and have lots of room.

 

[kev211]

I'm following "How to brew" and he says for a 5gal batch to start with 3gals in the pot so I figured I could start with 1.5 and have lots of room.

Oh gotcha. Sounds like you're gonna add the rest of the water to the fermenter then ya?

 

[MarcGuay]

You got it.1.5 in the pot, 1.5 in the fermenter, minus boil, hopefully that'll leave me with around 2.5.

 

[flars]

I get 3 gallon frosting buckets from the local grocery store. Nice O-ring in the lid for an air tight seal. Just need a hole drill for the airlock bung. They only cost $0.50.

 

[ziggurat]

I get 3 gallon frosting buckets from the local grocery store. Nice O-ring in the lid for an air tight seal. Just need a hole drill for the airlock bung. They only cost $0.50.

I'd second going with this if you find you enjoy doing this batch size. I modified a Mr. Brew Little Brew Keg (I know, it was a gift) using this method, and it makes for a half decent fermentation bucket now. Better for bottling IMO, but the option is there.

 

[MrBJones]

I get 3 gallon frosting buckets from the local grocery store. Nice O-ring in the lid for an air tight seal. Just need a hole drill for the airlock bung. They only cost $0.50.

Or get a 3 gallon carboy. Amazon has them for $30 delivered; probably $25-ish from LHBS.

 

[jerbrew]

I think it would work just fine. The concern is an infection starting on the sidewalls of the headspace before fermentation starts. Just sanitize very very well and it should be good. Once it ferments CO2 will fill up that space in no time.

isn't this true whether or not beer/wort is touching the wall?

 

[MarcGuay]

I get 3 gallon frosting buckets from the local grocery store. Nice O-ring in the lid for an air tight seal. Just need a hole drill for the airlock bung. They only cost $0.50.

Things like this are, to me, one of the major differences between the US and Canada. I have no idea what a frosting bucket is and nothing here costs 50 cents anymore!

When you drill the hole do you need a perfect bit for the size of your bung or do you trace the bung and then use a smaller bit to work it out?

 

[kev211]

Things like this are, to me, one of the major differences between the US and Canada. I have no idea what a frosting bucket is and nothing here costs 50 cents anymore!

When you drill the hole do you need a perfect bit for the size of your bung or do you trace the bung and then use a smaller bit to work it out?

Born and raised in the US. No idea what a frosting bucket is haha.

Bungs are tapered, so you dont need to drill a perfect hole. I would use a step bit (if you've got one) or a hole saw and drill a hole about the size of the midpoint of the bung

 

[TallDan]

Things like this are, to me, one of the major differences between the US and Canada. I have no idea what a frosting bucket is and nothing here costs 50 cents anymore!

Born and raised in the US. No idea what a frosting bucket is haha.

You're both overthinking it. It's just a bucket that a bakery gets bulk frosting in. They're airtight, made with food grade plastic, and to a bakery, they're trash. They will often give them to you if you ask, or take a very small payment. Don't be surprised if the bakery staff pockets the money and smiles because you just did them a favor.

 

[kev211]

You're both overthinking it. It's just a bucket that a bakery gets bulk frosting in. They're airtight, made with food grade plastic, and to a bakery, they're trash. They will often give them to you if you ask, or take a very small payment. Don't be surprised if the bakery staff pockets the money and smiles because you just did them a favor.

Ohhhh haha. Im sitting here going "why does somebody need a bucket to frost something? Just put it in the dang fridge!"

Derp

 

[RM-MN]

Hi folks,

Can I use a 6gal primary fermenting bucket for a small 2.5gal batch or does the amount of headspace for air make a difference?

Thank you
Marc

Would you care to calculate the headspace on this batch from Anchor Brewing? http://www.anchorbrewing.com/blog/w...8/Anchor-Steam-Beer-open-fermentation-500.jpg

Short answer: Your 6 gallon bucket is just fine for primary fermentation but not for a secondary. Most or us have finally realized that we really don't need a secondary for our beers.

 

[MarcGuay]

Would you care to calculate the headspace on this batch from Anchor Brewing? http://www.anchorbrewing.com/blog/w...8/Anchor-Steam-Beer-open-fermentation-500.jpg

Haha, I misread and was expecting to be lead to some kind of calculator or chart. Thanks.

 

[Knkbrand]

You will be just fine in a 6 gallon bucket. CO2 is heavier and will act as a blanket over your beer. no worries. As people have said, secondary is a different story, because when you transfer, you loose that blanket.

 

[TallDan]

You will be just fine in a 6 gallon bucket. CO2 is heavier and will act as a blanket over your beer. no worries. As people have said, secondary is a different story, because when you transfer, you loose that blanket.

ugh. This is a nonsensical homebrewing old wives' tale. There is no co2 blanket. Gasses don't behave that way. But co2 will fill the headspace during primary fermentation and push oxygen out.

 

[MarcGuay]

Hi folks. It's been ~40hrs since I pitched my yeast into 2.5gal of wort in a 7gal bucket and there's no action in the airlock. I'm telling myself that it will take longer because the CO2 needs to fill up the headspace before it starts to escape the airlock - does this make any sense, or would I see the oxygen being pushed out by the new gas production if there was any?

(Opened it up and took a sample, the gravity is falling and there's foam on top so I guess it's fermenting. The seal on the lid seems fine, no idea why the airlock isn't bubbling.)

 

[ncbrewer]

Don't open the fermenter if you don't have to. You can check for kraeusen by darkening the room and setting a flashlight on the lid shining down. Kraeuson will show up on the side of the bucket. It's a little crude, but way better than opening the lid.

I use a 7.9 gallon bucket fermenter for 4.5 and 5 gallon batches, and it works well. One advantage is with that headspace, I don't need a blow-off tube. The kraeusen never gets near the top.

 

[RM-MN]

Hi folks. It's been ~40hrs since I pitched my yeast into 2.5gal of wort in a 7gal bucket and there's no action in the airlock. I'm telling myself that it will take longer because the CO2 needs to fill up the headspace before it starts to escape the airlock - does this make any sense, or would I see the oxygen being pushed out by the new gas production if there was any?

(Opened it up and took a sample, the gravity is falling and there's foam on top so I guess it's fermenting. The seal on the lid seems fine, no idea why the airlock isn't bubbling.)

I have buckets like that. Some seal well and the airlock bubbles but all it takes is a tiny leak and you will get no bubbles. That's OK, bubbles only mean that there are no leaks and that there is an exchange of gasses due to a pressure differential. Your beer is fermenting and that is what matters.