I have been making wine from grapes at home for several years and never encountered this problem. During the primary fermentation stage I noticed some mold on the top of the cap of some in a few of the primary fermenters. I am working with alicante and grenache grapes for the first time and have heard that this is not uncommon with these grapes. As I said before, I never encountered this before. the weather here has been exceptionally hot, in the 70s during the day and 50s at night.
I removed the cap with the mold and set these primary fermenters aside. Any ideas about what I should do? I appreciate your help. Orlando