I made the lacto-fermented rhubarb fool recipe on your website in May with the hopes of preserving it for the winter. It worked well and tasted great. I left it in a half gallon jar in the fridge and recently moved it to the fridge door. When I looked at it again today, I noticed a slimy film on it. It doesn't smell bad, but it looks pretty bad. Do you have any ideas if it is salvageable?
I am happy to report that is just a small bit of surface yeast—called Kahm yeast. It is harmless. It can only grow where it has oxygen.
The best way to resolve this is to skim off the yeast one top and then put the rhubarb into a new smaller container. This will help control any population of yeast that is hanging out in the jar ready to go back to work when you remove it. More importantly a smaller jar will have less head space for oxygen to hang out and should solve the issue.
I hope that helps,