MLF overflow

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Junior Member
Feb 26, 2013
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I searched the forum a bit and see others have had wine overflows. I am trying to figure out from the knowledgeable on how bad I screwed up.

My Pinot Gris has gone thru primary. Last night I racked it into carboys and I see no more bubbling at the airlock and I assumed it was finished. My PH was 3.1. My original brix was 22, currently reading about 5.5, I believe that pretty much takes me to 0 brix if I am doing the alcohol adjustment correctly. I mixed up my MLF bacteria with some nutrients, gave it 15 minutes on the counter to do its thing. I pour it into the carboys and immediately the 4 carboys go into volcano mode. :slp

I accidentally didnt put my bacteria back in the freezer last night after using some on my Pinot Noir. I guess I didnt kill it by leaving it out of the freezer :h Noir did not bubble at all when I added it.

So was I not all the way thru primary and had a stuck fermentation, is this natural, were the bottles to full, .....the volcano lasted about 5 minutes, lots of bubbles, and even though I not currently overflowing, the air locks are bubbling pretty good when I put them back on.

Help :(


Veteran Wine Maker
WMT Supporter
Jan 1, 2007
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the heavy CO2 in the juice caused the volcano. the particles of frozen bacteria and nutrient into the wine provided a nucleus for the CO2 to cause effervescence.
I would have waited three days to rack off of gross lees and then added bacteria.
pinot grigio is not normally benefited with a malo fermentation.

another thought were you using a refractometer for final measurement. if so your conversion may be in error and the wine was still fermenting again a reason for effervescence once theparticles are added. I would suggest next time insure the measurement is stable for a few days before assuming fermentation is complete.
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