One bottle of 7 is making bubbles...

[Chevette Girl]

I just went to check on my quick-meads (my term for JAO variations when I label the bottles). I bottled 3 gal of blackberry mead into 1/2 gal jugs in March and one bottle now has bubbles in it. I always bottle my quick-meads in something with a screw top or a cork cap just in case they weren't quite done, that way I can check if anyone's building up pressure without having to uncork a bottle and if I do find a batch that's still fermenting, I can release pressure on all bottles of that batch without having to recork everything.

By the amount of sediment in that bottle compared to the rest, it was probably the last one bottled (if it's hard to fill the last bottle I will take a bit of sediment over the headspace) and should have been the first one drunk, oops... Anyway, I noticed bubbles at the waterline but when I carefully unscrewed the cap with my eyes squinched shut after moving adjacent bottles out of the blast radius, there was no hiss to indicate any pressure buildup, but when I agitate it, it sure seems to be releasing a lot! All bottles and caps were scrubbed with pink chlorinated cleanser and then sanitized with k-metabisulphite and hung on a sanitized bottle tree (not the caps but you get the idea). Could just that bottle be degassing? Or maybe there was enough yeast in the sediment the racking tube sucked up to keep things going?

I'm wondering if anyone else has ever had something like this, where different bottles from the same batch behave differently?

 

[skunkboy]

Any odd smells or flavors?

 

[wayneb]

Part of it is certainly possible residual de-gassing. Additionally, one thing to keep in mind is that any bottle containing some of the lees will have yeast that undergoes autolysis as the bottle ages. When that happens, "stuff" (i.e. complex polysaccharides and various amino acids and proteins) will be released into the mead, and that will tend to increase the surface tension of the liquid. As a result, any gases also released will tend to form more tenacious bubbles than those that would be found in thinner liquids.

That might be part of what's going on in your one bottle. The increase in surface tension coupled with any additional CO2 generated by a little more fermentation, or de-gassing as a little CO2 left over from active fermentation, will cause bubbles to form and to stick around longer. If you aren't noticing any pressurization of the mead when you crack open the top, then the amount of residual fermentation is probably pretty insignificant.

 

[Chevette Girl]

Nope, no odd smells or anything, just a lot of sediment...

Yeast autolyzation, that could be it, never thought about it before... and maybe when I go crack it open to drink it I'll see if the SG is any different from the others...

I've had no-pressure degassing happen with a few bottles from another batch (my first mead) but a couple of those did make meadsplosions when agitated...

 

[Medsen Fey]

Anyway, I noticed bubbles at the waterline but when I carefully unscrewed the cap with my eyes squinched shut after moving adjacent bottles out of the blast radius,

Your eyelid will not stop an exploding glass sliver from penetrating your eye. When you deal with wine bottles that may have refermentation occurring, you should wear goggles and gloves. Yes, I know that most of the time that will be overkill and not needed, but for that once-in-a-lifetime bottle that really explodes, the consequences could be devastating. I mean, seriously, who wants to wear an eye patch - you'll have to dress as pirate for Halloween from now on.

Placing them in a fridge or freezer to cool them down and reduce pressure may also be a good idea.

Without the exact recipe details it is hard to say exactly what occurred in your bottle, but if it was continued fermentation, the other bottles may not be far behind. Having a smaller dose of yeast, they may be slower to develop. You've described some of your other batches, and it seems you sometimes have incomplete fermentations. In that case, if you are going to bottle a quick mead, you should strongly consider using sorbate/sulfite to prevent refermentation.

 

[Chevette Girl]

Thanks for the stern reminder, Mesden. If I find a cheap face-shield that doesn't require a construction helmet at Princess Auto I may invest...

I wasn't being completely idiotic, as I already wear corrective eyeglasses of a lens style that has already proven they can take a hit, and I was willing to take the risk to my hands as I unscrewed the cap, if it had been corked I'd have been a lot more apprehensive. And I figured unscrewing the cap was less likely to trigger a potential bottle-bomb than two flights up the stairs to the refrigerator, if it'd been corked I'd probably have wrapped it in a blanket and given it an hour or two in the basement chest freezer.

And most of the time my quick meads are pretty stable even without chemicals. I resist using chemicals if I can avoid it, too many friends with sensitivities.

I do check all my bottles every couple of months (like burping tupperware or topping up airlocks) and usually there's nothing happening with any of them.

In this case it slipped under the radar, I didn't notice because the situation was slightly outside of my standard methods...this is the first big batch of quick mead I've ever done and I bottled four batches at once (most I've bottled before is two gallons at a time) so it went unnoticed, usually I keep the last bottle with the extra crud in it upstairs to monitor (and sample) and if there's a hiss when I open it (for aforementioned sampling!) I know to check the rest of the batch more often. In this case, I left the last bottle downstairs and the bottle for sampling went to a friend's place and I only had samples of the other two on the kitchen table under observation... After the one batch of lemon-date that started pushing its corks out (which was when I stopped corking JAO variations), the only other quick mead I had this happen with was the strawberry, and both jugs burped a little for a couple months then stopped... guess the agitation of being bottled gave the yeasties one last gasp.

 

[Chevette Girl]

So I stuck an airlock on the bubbling one and kept an eye on the rest of the bottles (loosening the lids every week to see if there was a hiss) and two more had started to bubble earlier this week so I brought them all upstairs again, after the heat wave this week they were all starting up again... so I've emptied them all back out into a carboy and added a bit more bread yeast and we'll see if we can't get it to finish already...