Hello forum members! First post here...
I know this thread is kinda old, but I'm wondering why vegetable oil (like olive oil), would be "bad" for the yeast if used as an antifoaming agent. Several years ago I was in a R/D lab doing bread-yeast propagations in industrial fermenters and I'm pretty sure the antifoaming agent was vegetable oil based (but not 100% sure).
I don't see how it would also give me off-flavors because I only plan to use 2-3-4 drops for krausen control in starters. As I plan to throw away the starter beer and only want to harvest the slurry, I'm guessing the remaining oil will be infinitesimal. When harvesting, I'm thinking I should just POUR down half the beer in the sink so that the surface oil will go away and then siphon the rest.
I'd probably do a 5 liters starter using a WLP400 liquid vial.
What are your thoughts?