Do cork bungs behave differently from rubber?

[MrsCordial]

Since I split out that over-sweet wine and redid it, I've had to use one bored cork bung with an airlock rather than the rubber bungs (with airlock) I've always used before simply because I needed them fast and the pharmacy was out of rubber bungs. I can see the wine fizzing away, but no air is coming through the airlock. Is it seeping out through the cork instead? The other DJ with the other half of the concoction in it and a rubber bung and airlock is blooping away quite normally.

[Mikey]

I wouldn't have thought the cork would make a difference MrcC they do still use cork on shampoo bottles and that doesn't let the fizz out.

Perhaps its a dud.

[Samurailord]

It may not be the cork itself, but the seal between the cork and the neck of the demi john where the problem lies. This can happen if the cork has been allowed to dry out too much - its always a good idea to soak your corks in sterilising solution for a few minutes before using them anyway, which helps to stop this problem.

As long as the contents are fizzing there is no need to worry, but when fermentation has slowed or has stopped try to rack it off as soon as you can, and then use a thin layer of vaseline or petroleum jelly on the cork if you need to re-use it as this will allow for a tighter seal for the DJ.

You can also get a similar problem with rubber bungs as they age and perish, but you can't re-hydrate them so will have to replace them when the time comes.

Andy

[Kirk]

I have used both and I am getting to go for the rubber option more and more. I just have less problems concerning what you describe. I find I can end up trying to seat the cork ones so many times and getting the airlock to be air tight that I dispair.

Would prefer cork but for the experienced ease of the rubber ones they are what I usually grab first.

The advantage I find of the cork bungs is that you can boil/cook/soak them and so they are a bit more adaptable.

[MrsCordial]

That's really interesting everyone, thanks. I've got on well with the rubber bungs and would have bought them this time if they'd been available.

I've just learnt that a Wilko is opening in Hereford next month - I'm thrilled as it's been mentioned so often as a great place for home brew kit. I've also found that Philip Morris sells things too so will try to support them as well, esp as it was the only place within striking distance that could provide me with cider yeast on Saturday.