Yeast and pressure

[Asahikun]

Hi guys,
Haven't been around much lately; life just keeps getting in the way of surfing, but not brewing!

I went to a new HBS a few weeks ago and was told something that really surprised me. This was said by someone who has been brewing for years and has apparently won many a competition.

The gist was this: you should brew in a bucket with a loose-fitting lid and not in a fermenter with an airlock because beer, unlike wine, should not be brewed under pressure. This is due to the fact that the yeast will work more quickly if they are not under any sort of pressure.

Can anyone shed any light on this?

[toneyc]

That's the beauty of the airlock. It allows gas pressure to escape while preventing entry of bacteria. There is no buildup of pressure unless your airlock gets clogged.

:eek:
Toney.

[danno]

just a guess here, but maybe he doesn't know what he's talking about? there is a small (teeny) bit of pressure required to move that little bit of water out of the way, but it's gotta be less than even usual weather variations...

[Tweek]

Originally posted by danno
just a guess here, but maybe he doesn't know what he's talking about? there is a small (teeny) bit of pressure required to move that little bit of water out of the way, but it's gotta be less than even usual weather variations...

Im with Danno on this one.

[brewmonkey]

Actually there are a ton of studies done in the recent past on fermenting under pressure to decrease the time spent in primary.

Do some googling on it and I am sure you will find some info on it but I am going to say that your local HBS guy is off his rocker just a wee bit.

[Asahikun]

Thanks for the replies.
I don't why I believed it at the time. The spiel was just so convincing though. I now find myself brewing in a bucket with a loose-fitting lid. It seems to be working OK though.

Am I right in thinking that the chances of infection once fermentation has started are pretty slim because:

(1) At the start, the outward pressure is too great to allow anything in
(2) Later on, the presence of alcohol means that infection is very unlikely.

Am I way off here?

[danno]

never say never, but pretty much you're right...

[guildofevil]

I always brew in a bucket, with loose fitting lid and have never had an infected batch (knock on wood).

Séan

[toneyc]

That's because you're Irish and the rest of us aren't so we have to take precautions.

:D
Toney.

[HogieWan]

Is my irish ancestry the reason for not yet having an infected batch regardless of my less-than-strict procedures?