I could have sworn that there was a published article recently about how it is good to let the finished fermentation sit for a bit before distilling, especially with open fermenters. It went on to explain how the lactic acid bacteria, and other bugs go on to produce some interesting flavors while your ferment sits there and those flavors add character to the final distillate.
Obviously this is assuming you don't strip everything out of the distillate, probably would be more applicable with a pot still run... Either way I’m not an expert.
As long as you don't mess with it, It should be good for 5 days or so. You will know when it needs to be run before you are. It might start to get a whitish film on it "BAD" run ASAP. Or start to smell funky then Run it. I have racked and gone a week without either, and no problems. I have made runs with the film and it does change the mouth feel but not the flavor so much. It goes away with a second run. All done in pot stills.
Just my 2 cents
I like to get to it as soon as it finishes out, unless you have cooling on it and can crash it to around 40 F. If you're harvesting yeast, this helps flocc it out, as well.
I often see growth on the top of the ferments at other distilleries. I hear a lot about Lacto, but I'd say more than 90% of the films I see are classic pediococcus. Depends on your environment, container, and wash material, mostly.
Great info guys! Thanks