I am day 3 in fermentation and twice I have gone to stir the must only to find the lid was propped open from the bag pushing up on it. Will this ruin my wine? Should I transfer to my 6gal bucket for more head space? or should I let it ride?

5 Answers 5


Your fermentation bin should be airtight otherwise your wine could turn into vinegar. You could use a blow off tube or move into a bigger sanitised bin. Either would stop this from happening.


If the bag (presumably with ingredients) floats to the point where it pushes up the lid, that means you have two problems here.

  1. The fermenter lid should be closed at all times except when CO2 pressure pushes it up momentarily to "burp off" the excess pressure. A better way is to fit an airlock. As stated above, your current setup puts you at risk of microbial contamination.

  2. If the bag of ingredients floats that high, it means it is not properly submerged in your must which means the contents will not be properly involved in the extraction process. Weigh it down (using sterilized glass marbles works well) to keep it where it belongs.


If this is a red wine and the must is pushing open the lid, there is no concern here. Wineries often times purposely open ferment (using a breathable lid) for red wine. Also, you may need to punch down the bag several times per day. This is completely normal for fermenting grapes as apposed to juice.


if its from normal co2 production i would put an air lock in the lid if that should fix the issue


during primary fermentation why would you put wine must in an airlocked container? Most winemakers ferment in a somewhat open bin and may cover with a towel. Secondary fermentation requires the the airlock. As long as your wine is above negative brix, you will be just fine.

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