richardtmorgan
Active Member
I've started using a new technique to ferment my higher gravity beers. I ferment open (i.e. with the bucket lid on, but not sealed) for the first 36 hours, and then seal the lid for the remainder of the fermentation process. Anyone else doing this? Any thoughts?
I used to open ferment all my British Bitter for the whole fermentation period. I never had an issue with contamination. For my regular beer I now aerate, seal the bucket and use a three piece airlock (why take a chance?).
However - a bit of a mess with a high gravity beer fermented with s-04 meant that I needed a different solution.
My choice has been open fermentation while the fermentation is getting started and while it is very vigorous followed by sealing the lid once the fermentation has slowed a little. In reality this means if I brew on a Saturday I seal the fermenter first thing on Monday morning.
My theory is this: In the first hours after pitching the yeast need as much oxygen as possible - the open fermentation assists this. As fermentation takes off, the yeast are producing lots of co2 in these higher gravity beers. Because the co2 is heavier than the air it produces a natural blanket on top of the wort. At 36 hours the fermentation is still strong enough to be producing a good co2 blanket, but not so strong to risk blow off - so it's safe to seal the fermenter.
The advantage is that it's very straight forward and there no mess to have to clear out of a blow off tube.
I use this technique any time I ferment a high gravity beer with a fast fermenting yeast.
Has anyone else done this and have you had any issues?
I used to open ferment all my British Bitter for the whole fermentation period. I never had an issue with contamination. For my regular beer I now aerate, seal the bucket and use a three piece airlock (why take a chance?).
However - a bit of a mess with a high gravity beer fermented with s-04 meant that I needed a different solution.
My choice has been open fermentation while the fermentation is getting started and while it is very vigorous followed by sealing the lid once the fermentation has slowed a little. In reality this means if I brew on a Saturday I seal the fermenter first thing on Monday morning.
My theory is this: In the first hours after pitching the yeast need as much oxygen as possible - the open fermentation assists this. As fermentation takes off, the yeast are producing lots of co2 in these higher gravity beers. Because the co2 is heavier than the air it produces a natural blanket on top of the wort. At 36 hours the fermentation is still strong enough to be producing a good co2 blanket, but not so strong to risk blow off - so it's safe to seal the fermenter.
The advantage is that it's very straight forward and there no mess to have to clear out of a blow off tube.
I use this technique any time I ferment a high gravity beer with a fast fermenting yeast.
Has anyone else done this and have you had any issues?