Cyser bubbling again after terminal 1.0002

Have a cyser OG 1.092 FG 1.0002 with Lavlin D-47. Racked to carboy 7 days ago at 1.0002. No airlock activiy no bubbles for 5 days. Now have significant airlock activity (1Xevery 10sec) and can see many bubbles rising. Is this malolactic fermentation or could it be more insidious bacteria doing their work. I can’t smell any diacetyl.

I ran out and got some lysozyme to stop the geranium effect (which I now know happens only in conjunction with K-Sorbate). I do plan to backsweeten, but maybe in a year at bottling.

I have some K-metabisulfite as well.

If it is malolactic fermentation I think I will let it go. That way there will be no danger of geranium flavor/aroma when I do add the K-Sorbate.

If it is a different kind of bacteria that will ruin my batch I want to stop it ASAP. How do I know?

If I do want to stop this do I add lysozome and K-metabisulfite? Just K-metabisulfite? I’ve read conflicting reports about K-meta (that it just inhibits rather than kills bacteria). I also have a chest freezer that I can cold crash. I put it outside for the night.

Yep, sounds like malolactic. I would just let it go.
Have you checked the acid level?

pH origonal 3.57
pH final 3.51

Thanks for the reply Baritone,

I have been looking around at malolactic fermentation info and it seems that it is mostly done by pure culture to avoid off flavors. I may have an unfriendly strain of lacto, pedio or oenococcus.

I fermented this batch in a bucket doing the staggered nutrient additions so the lid was opened every day to add or stir. The chances of introducing something bad at a high enough level to take hold are pretty good.

I actually have 2, 6 gal. batches I did side by side that are doing this. Quite a bit of money and time invested. I have the lysosome ready to deliver, but if no off flavors are coming then why bother.

I got a test kit from White Labs some years ago to test for Gram+ bacteria. This test would be useless since all of the bacteria that convert malo to lactic are Gram+.

I guess the only thing to do is take samples and check aroma/flavor if it starts to go bad hit it with lysosome. I have the K-metabisulfite too but I don’t know which to add. Seems like K-meta should do the same thing for way cheaper (I may return the lysosome $25).

Doesn’t sound like you have to worry about acetobacter at this point. I don’t think you have anything to worry about if your santitation was good. I do the same staggered nutrient feedings and stirring with mine.

Just racked for cold storage for winter. Temp corrected FGs:

Nottingham- 1.004
D-47 - 1.001

The D-47 is more complex.

They have mellowed a bit, who knows if it is from the suspected malolactic fermentation or just normal aging. The good news is that there are no off flavors. They are both very tart, but from previous experience this seems normal.

They aren’t “topped up”. My last cyser wasn’t topped up in the carboy and aged for 7 months there. I didn’t notice any obvious acetic acid production.

I shot a blanket of CO2 on top. Also there is some slight offgassing going on still. is this sufficeint or should I go buy some marbles?


Personally, I would not leave it for 7 months without topping up. And would rack it an additional time or two as well.