tylersmalley

The vacuum sealer uses heat to seal special bags. You re-seal the same way you seal it originally by placing the part of the bag with a corner cut off in the machine and turning it on. The bag will get a bit smaller each time, but even for long ferments I don't need to do it more than 1 or 2 times. I just make sure to size the bag originally to account for it.

The Noma Guide to Fermentation mentions using a vacuum-sealed plastic bag. I find this much easier to manage. You will only need to "burp" the bag by cutting a corner off, releasing the air then re-sealing.