View Full Version : Low pressure system & degassing disaster?

David Baldwin
06-10-2005, 08:05 AM
Go figure. For the first time in weeks, I didn't check on my mead each morning and night.

So this morning I went down to find that my finished and bulk aging pyment had popped the rubber stopper I had in the carboy.

I know it had quit fermenting - it's fermented dry - and the rubber stopper is MIA.
I think that what happened is that having stoppered it, the mead was unable to degass, and we had two sudden low pressure systems sweep through with some spectacular thunderstorms. I suspect that the stopper while tight was no match for the significant pressure differences when the storms came through.

Anyway, I am now worried about the integrity of this batch. It's at about 16% ABV, and I did not use any sulphites to stabilize it.

Should I now add sulphites to prevent any long term surprises? There had to have been some oxidation, but the carboy was filled to the neck, so there was little surface area exposed.

Lesson learned: forget the stopper, and leave it airlocked.


06-11-2005, 02:28 AM

How long a time are we talking without the cork? Overnight, or more like 24 hours? Of course, it only takes a moment for a nasty bit of microbiota to get in and ruin your mead, but with 16% ABV, I don't think I'd be too worried about wild yeasts. It's those bacteria you'd have to worry about -- either carried on air currents, or, more seriously, carried by fruit flies. How big a batch is it? If it's just a gallon...heck, I'd just drink it young and be done with the worry. A bigger batch would be tragic to lose, though. In this case, I think I'd go with sulfites.


Dan McFeeley
06-11-2005, 07:45 AM
Hello David --

Pressure changes could have been one factor, but temperature changes in your storage area would be another, possibly the primary factor. Maybe a combination of the two, both working together to release dissolved CO2.

I've had it happen to me too and learned the same lesson -- keep the air lock on the carboy long long afterwards. Interestingly, damage to the mead varied. One mead was unaffected by the exposure to O2, even though it had been open to air for about a week. The other took on a bitter taste which took a lot of work to get out. Both were traditional meads.

It taught me something about the varying properties of honey. Honey has antioxidant properties, but, as all things honey, these vary according to floral type and even the individual honey.

It's too late to add sulfites. Sulfites are a preventive measure against oxidation. Once exposure to oxygen has occured, it's too late to undo any damage that has been done. Kind of closing the barn door after the cows have escaped.

I'd suggest stoppering it up, letting it bulk age for a good long time, and then bottle it. Then age it some more. Sufficient time may be sufficient to correct any flaws. If anything, the combination of the phenolics from the grape along with the honey may have been enough to stave off any oxidation damage.

David Baldwin
06-11-2005, 10:26 PM
Many thanks for the input.

I can't say for sure how long the stopper had been off. It could have been as long as 48 hours without the stopper, but there's really no way to tell.


Temperature may have been some factor. Local temps have been in the 80's, but my carboys are kept in the basement where the temps are quite a bit more constant. The shift in barometric pressures was significant and sudden. The resulting thunder storms were spectacular.

While worried about oxidation, I'm more worried about bacterial infection. Would the sulphites be of any benefit to prevent a bacterial infection?

06-12-2005, 03:04 AM
Toss in some oak cubes, they'll help to balance out any oxidation that may have occured. Then bottle em up and let em sit. Dan was right on the money.

Sulfites certainly won't hurt at this point, but, they won't undo the oxidation, and they will help to bring your mead to a bacteriostatic level before you bottle.

Hope that helps,


David Baldwin
06-12-2005, 08:41 PM
Excellent idea Oskaar,

I've got some oak that I've toasted and is waiting for some mead to swim in.

So it's a prescription for oak and age then. I'll let you know in December how it turns out!