Quick question - conflicting info on interwebs, but Im guessing the led light I have over my brew area is harmful to the yeast starters sitting on my stirplate? I havent had issues yet with yeast, but wondering if I should wrap a towel around the flasks when Ive got a batch of yeast starting up the day before brewing…
I’ve had yeast sit where there’s sunlight, incandescent, fluorescent, and LED, and never occurred to me that it might affect yeast. Never had a problem so far as I can tell. Wrapping it up could trap heat, and that’s a known vs. unknown or hypothetical danger, would be my thinking.
I keep my starters in my kitchen and have never worried about the light affecting them. If you add hops to your starters then I would be concerned about light exposure. Just my $0.02
From what I’ve read, ultraviolet light will cause hopped beer to get skunky. Pretty much you need to beware of florescent light and sunlight if you hop your starters. O have always fermenter mine on the kitchen counter, where they are intermittently exposed to both without a problem. You might be able to do a search and find what part of the spectrum your particular LED light emits.
If you’re in your garage for hours on end under those lights and aren’t getting sunburned, then the yeast are fine. If you’re concerned, just leave a glass of IPA under the lighting for a while (~5-10 min) and taste it. If skunky, then the lights are blasting out UV rays, in which case the yeast should be the least of your concerns.