Fermenter size

[Paddington]

I usually brew 10 litre brews. I'm not happy with the quality of my 10 litre fermenters and I'm looking to buy some new ones. I'm thinking of getting a couple of 15 litre buckets to give me more flexibility to brew 10 - 15 litre at a time. Is it OK to brew 10 litres in a 15 litre bucket without risk of infection? I'm sure the CO2 will be enough to protect it, so I'm just after reassurance. If that's ok, would a 10 litre brew be vulnerable in a 25 litre fermenter?

[Fil]

Yes, the pitching of a large yeast population and quick growth period when the dissolved o2 is exhausted should provide you with a vigorous fermentation that will push out a large volume of co2 blanketing your brew in no time whatsoever ?

go for it

[PeeBee]

To backup Fil's reply:

I brew 45 litres in a 65 litre fermenter (which has about 15-20% headspace for 65L). Bigger quantities but the proportions are the same. It never crossed my mind to think that much headspace would be an infection risk. Nor should it have had.

[vacant]

Sugars ferment to roughly equal weights of alcohol and CO2. e.g. if you end up with 1 Kg alcohol in 23 ltr (approx 4%) then 1 Kg of CO2 is 560 ltr!

If by "quality" you mean old and scratched then for regular cheap replacements I have fermented in a Wilko's storage container (these have a food safe mark) - various sizes, mine is 65 ltr for a 40 ltr brew, and currently in my fridge I have a brew fermenting in a 25 ltr plastic jerry can water container - if you buy one with a tap in the lid it's easy to attach a blow off tube.

I have to clean the jerry can with hot liquids which takes a bit more effort but it simply can't get scratched inside. Also, before pitching I can fill it with 10-15 ltr, close the tap and aerate it by shaking before adding more wort.

[nigelnorris]

I make mainly 15L batches. I start them off in a 30L FV and then transfer them into 15L secondaries when the time comes. 30L gives plenty of headspace, I've never needed a blowoff although it's probably still possible, and 15L gives very ilttle headspace, which I figure reduces the likelihood of contamination or oxidation.

[Paddington]

Thanks for all the advice. It's kind of what I thought, but reassuring to hear from others.

[Fil]

Sugars ferment to roughly equal weights of alcohol and CO2. e.g. if you end up with 1 Kg alcohol in 23 ltr (approx 4%) then 1 Kg of CO2 is 560 ltr!

If by "quality" you mean old and scratched then for regular cheap replacements I have fermented in a Wilko's storage container (these have a food safe mark) - various sizes, mine is 65 ltr for a 40 ltr brew, and currently in my fridge I have a brew fermenting in a 25 ltr plastic jerry can water container - if you buy one with a tap in the lid it's easy to attach a blow off tube.

I have to clean the jerry can with hot liquids which takes a bit more effort but it simply can't get scratched inside. Also, before pitching I can fill it with 10-15 ltr, close the tap and aerate it by shaking before adding more wort.

ooooo those numbers are bound to lodge and get regurgitated when forum browsing after a sampling session... if i were to post ELSEWHERE!! 'Hundreds of litres generated in a average 5 gallon batch'.. how long before the myth machine multiplies that to 1000's i wonder??

[rowettbrew]

I typically brew 100L batches in a 238L fermenter (sometimes I do double batches, which is why I bought the big FVs). Never had any problems with infection or oxidation - there's plenty of CO2 in there it seems.