Barely discussed in the paper: bubbles.

Many fermentation processes produce gas, and some aerobic fermentation processes happen while fully exposed to the air. Gravity provides quite a bit of assistance separating gas bubbles from solids and liquids.

In space, how do you build a fermentation airlock? With a centrifuge? Can you safely punch down dough? How do you open a sealed, pressurized container of anything carbonated? Can you easily remove enough dissolved CO2 from your kimchi so that eating it won’t make you burp?