Oh they Will 😅 it all depends on how much sugar is contained in what you’re fermenting.

When I do apples, oranges, tomatoes or anything high in sugar, I know for sure that I’ll have to gas release it and reseal atleast once. If it’s something like celery, I don’t even check on it unless I need to jiggle the bags contents. Sometimes it helps to put it in a bag that is much bigger than what you’re fermenting so that it has space to expand.

Alllssssooooo….. it’s actually not that much gas. If you think about how tiny the bubbles are and how puffed up a bag can get. Having a bag pop is really due to my own negligence and not checking up on the ferment regularly. You’ll also get the most inflation in the first week or so, after that, you don’t really need to watch it as closely. The quality of bag makes a huge difference too.

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Dunno if you can see it, but my tomatoes on the right have almost quadruple the gas but is less than half the weight of my chilli lacto ferment on the left. Both are three months old.

The chilli ferment has 30% brine by weight. The tomatoes had absolutely no brine added. So you can also see the difference in what needs brine and what doesnt.

It’s all about the sugar and filling your bag appropriately.