I've recently made a bottle of spinach kraut by following one of your recipes. And when it was done, I put it into the fridge. Only after a few days, I saw a "white ring" at the bottom of the bottle. I've attached a picture here to explain better. Do you know why that happened? And is it still safe to eat?
The white ring at the bottom of your ferment it fine and a normal part of fermentation. It is similar to the sediment at the bottom of pickles (like Bubbies brand or home fermented pickles). I am happy to report it is very normal and harmless. I believe you are seeing it because the spinach ferment is darker in color than most. If you look carefully at other ferments you will likely see a similar ring.