Originally Posted by ColoHox
Also, UV exposure most certainly affects yeast.
[QUOTE=emyers;4915194Yeast DNA is damaged by UV rays.[/QUOTE]
I can't argue with the referenced link. Maybe they exposed the yeast to high amounts of UV radiation. Yeast survives in the open, it naturally occurs in the open. Natural fermentation of cider is with the yeast from the skins. Natural fermentation of wine is with yeast from the grapes. We capture yeast from the air for 'wild' brews (and a lot of is it sacc yeast).
Maybe high amounts of UV radiation affect yeast, but I think just sitting in the window is not going to do anything to it.
Humans are affected by UV radiation. If we sit too long on the beach catching rays for way too long, we might get skin cancer, but walking about in the open is not considered harmful.
For the OP ... Your yeast will be fine.