Ferment Restart after 18months

Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum

Help Support Homebrew Talk - Beer, Wine, Mead, & Cider Brewing Discussion Forum:

This site may earn a commission from merchant affiliate links, including eBay, Amazon, and others.


New Member
Apr 28, 2014
Reaction score
Hi all,

Long time lurker, first time poster as I have a really weird quandry. I've now been meading for 3 years, however I'm now just still learning as it takes over a year to realize you've made a mistake. I've now had two brews which, after a year or more of bulk aging, restart ferment at bottling.

Now is where I would love to give recipes, but my hard drive failed me a year back and all notes are lost to the ages. First one was a peach and the second a blueberry, both D47 yeast. I primaried, then secondaried at the end of ferment. Both times ferment reignited at the primary-to-secondary, which I wasn't concerned about since I was planning to bulk age the hell out of them. I figured a year+ in secondary would ensure all the sugars would be eaten until the yeast killed themselves off.

Sure enough the peach ended up bottle bombing on me at bottling after 14 months of bulk age, and my most recent blueberry bottle bombed on me at 18 months bulk age, bombed after only 1 day in bottle.

Has anyone experienced this? Am I just waking the yeast up by disturbing/siphoning?

The wine tastes fine (the peach was great champagne), so it's no an infection. I would weigh SG over months instead of days before bottling, and still end up with wine on the floor.

Somone please help or my GF will end my meading quickly.
It is hard to say anything for sure without at least knowing the OG and SG of the mead.

Racking between containers could restart fermentation with a little O2 added to wake up the yeast. I had a couple peach wines with a specific recipe I have made that I found will only ferment if I add a little water with my sugar. If SG is at .996 or lower there should never be a bottle bomb situation but above that and it may be safe to add sorbate and Camden before bottling.
Are you carboys topped up to the bung when you bulk age? If not, an infection could take hold and cause some further fermentation by fermenting alcohol (vinegar bacteria) and other things not fermentable by wine yeast.

Or, are you attempting to sweeten the mead at bottling, without stabilizing first?
1. A mol of ethanol is 46 grams - or about 60 mL, however a mol of CO2 is around 22 liters, point being that if you have just a few dozen mL of vinegar being produced, a lot of gas is produced, and thus pressure. That is something to consider.
2. Why not sorbate/sulphite?
3. Cold crash and rack, cold crash and rack or simply swirl, let sit for a day, then bottle.
4. If the FG is above 1.005, see above.
What are you using for secondary? Bucket , glass carboy , better bottle? ( O2 permeability)

Also are you sure everything is santitary? I'm will to say you picked up some some bugs during secondary transfer that are chilling in the vessel then start going when you bottle with additional sugar.

I'm not calling you out but sanitation might be a possible issue.
Do you recall what the gravity might have been when you transferred the mead from the primary to the secondary? If you racked from the primary when there was still unfermented sugars you may have removed nearly all the active yeast when you siphoned. Over time those yeast may have multiplied enough to reactivate and referment the residual sugar.
Had the same thing happen to me last summer. Mead was well over a year old and was shooting corks across my basement a few months after bottling. Started check the gravity again and it was still going down. About 9 months later if finally leveled off (hopefully for real this time). My FG seemed high, should have known better.
Sorry I didn't reply earlier, thought I did but must have errored out.

For the Blueberry (the only one I remember off the top of my head) was put from primary into secondary at 1.01. At bottling it had been stable at .99 for about a full year, kept in secondary allowed 14 months bulk age. It's always difficult to measure sugars utilizing fruit, but should have come out roughly 14% abv which is right where D47 should have been able to take me.

Sanitation for my setups is always good and the bubblers always kept full of vodka. The flavor profiles were excellent, and I hate vinegar tastes so they'd stand out to me. I tasted both the bottle bombs and the non-explodes, all of which had also carbonated on their own. Since they all carbonated, it can rule out any acedo-bacteria in an unclean bottle.

Primary, and Secondary/Aging were both in 3gal glass carboys.

I'm out of ideas. I saved the mother from the Peach and used it for the blueberry, so I can only assume it was a was a crazy mutant strain of D47 which goes to sleep and wakes up with agitation. These were my 5th and 6th mead brews, and the first to ever have this issue.

As I said, out of ideas...