Hydrogen sulphide

[WalesAles]

You leave a foam bung on your fermenter for 2 weeks?

Jocky,
What`s wrong with that then?
I don`t use an airlock, just leave the FV lid slightly cracked open for two weeks, no problemo! Yet.
Covered with an old Duvet of course.

WA

Sent from the New Kitchen.

[IPA]

You leave a foam bung on your fermenter for 2 weeks?

Why not ?

[Jocky]

Oxidation?

[MarkA]

Oxidation?

I've never used an airlock on any beer (a square of tin foil with starsan does the job covering the hole) and have never had an oxidised beer, even after leaving a lager for 5 weeks. Where do these myths come from??

[Jocky]

Not myth. Personal experience.

And resultant feedback from at least a dozen other brewers across multiple beers.

These days I too open ferment with some foil over the fermenter opening, but once the fermentation starts to slow it's on with an airlock.

[WalesAles]

Oxidation?

Where do these myths come from??

Mark,
The Myths on the Mountains,
The Rivers running free...................

WA

Or was that `Mist on the Mountain`?
Time to stop drinking Rasp and Cran TC or what?

[MarkA]

Oxidation?

Where do these myths come from??

Mark,
The Myths on the Mountains,
The Rivers running free...................

WA

Or was that `Mist on the Mountain`?
Time to stop drinking Rasp and Cran TC or what?

or drink more....?

[Kev888]

There is probably a good middle ground in these things. The yeast and krausen offer significant protection against oxygen once things get underway; there isn't any great need for an airlock at this stage and there can be advantages with some yeast varieties to letting things breath more freely. Though I wouldn't say an airlock was inherently wrong, provided it was low pressure and appropriate to the amount of CO2 being generated.

Once things die down, the yeast still have some powers to deal with oxygen so I don't subscribe to paranoia about the slightest amount being allowed in; I'll happily open the lid to test things as much as wished, and dry hop etc. But these powers are now much reduced and there are no longer any benefits of allowing oxygen in, so IMO at this stage a sealed FV and an airlock start to become more beneficial.

This debate causes some controversy. I believe compounded by the (less than intuitive) way in which dissimilar gasses can mix; the concept of a CO2 blanket is overrated. Also, sensitivity to the flavours of mild oxidation varies between tasters, and is masked to a greater or lesser degree by different beer styles. Time in storage/maturation can also be a factor.

[Jocky]

All good points Kev.

To explain further - my own experience in this was back some years where I'd ferment with just a bit of foil over a 1 inch opening to the fermenter, and then leave it that way for 2-3 weeks before bottling. I was a big believer in the 'CO2 blanket'.

I always suspected some oxidation, but when I started going to a homebrew club I was told that the beers were very oxidised. In a couple of dark beers it wasn't noticeable, but pale hoppy beers were bad.

So I switched to using an airlock (something which I've relaxed now - I only airlock when fermentation slows) and my next beer in a competition - a Double IPA, scored 39/50 and won a rosette and I have been brewing largely oxidation free beers since.

With all that in mind it surprises me that a foam bung stops gas exchange to the point that it avoids oxidation over a couple of weeks, foil even more so.

I enquired out of curiousity and wanting to understand, not to be dismissive of other's practices.

[IPA]

Not myth. Personal experience.

And resultant feedback from at least a dozen other brewers across multiple beers.

These days I too open ferment with some foil over the fermenter opening, but once the fermentation starts to slow it's on with an airlock.

If it's good enough for Theakston it's good enough for me ! Did you get feedback from them
http://www.beerinfinity.com/uk-brewerie ... tadcaster/
they don't seem to suffer from oxidation

[IPA]

Not myth. Personal experience.

And resultant feedback from at least a dozen other brewers across multiple beers.

These days I too open ferment with some foil over the fermenter opening, but once the fermentation starts to slow it's on with an airlock.

If it's good enough for Theakston it's good enough for me ! Did you get feedback from them
http://www.beerinfinity.com/uk-brewerie ... tadcaster/
they don't seem to suffer from oxidation
Scroll down the link to see their open fermenter and then click on the image

[Jocky]

Not myth. Personal experience.

And resultant feedback from at least a dozen other brewers across multiple beers.

These days I too open ferment with some foil over the fermenter opening, but once the fermentation starts to slow it's on with an airlock.

If it's good enough for Theakston it's good enough for me ! Did you get feedback from them
http://www.beerinfinity.com/uk-brewerie ... tadcaster/
they don't seem to suffer from oxidation

If you're not going to bother to read what I've written then nobody is benefitting here.