If the starter was not hopped, you should be ok since the hops are needed to produce the skunky flavors.
The UV radiation in sunlight can damage yeast cells, but they are capable of self-repair to a degree, so there should still be plenty of viable cells to continue fermentation.
It's a good idea to not pitch the spent starter wort in general, here, I ...
Hops react with light to create skunky flavors. So long as you didn't use hops in your cider (not unheard of), you don't need to be overly concerned about light. I still wouldn't recommend fermenting or storing it in direct sunlight if at all possible.
While that paper is interesting. I think it applies more for ethanol production as a fuel rather than beer.
While light can effect yeast In good and bad ways, In general light is bad for beer.
This article explains what spectrums of light are worse than others.
According to Beer Advocate,
This is when the beer has been exposed to ultraviolet light for a period of time. Hop-derived molecules, called isohumulones, are basically ripped apart.
So unless you're adding hops to your starter (which you shouldn't be), light shouldn't be much an issue.
Really depends if you use hops or not. I always put a few pellets in for thier antimictobial properties.
And it depends when and how you pitch your starters.
Light + hops would be bad If your starter is just to reduce lag time ie pitching it at high krausen. While this is common it's mostly of those that have never tasted a starter and ignorantly add all ...
This Wired article may help shed some light on wavelengths and bottle colour.
Light in wavelengths of 350 nm to 520 nm (upper UV to mid-visible light) is known to cause skunky beer.
Green bottles allow green light (520 nm to 550 nm) to pass through, whereas brown bottles (ranging ...
While light might have a slight effect on cell growth, the question is whether or not it's worth the hassle. Keeping in mind that if this were a good idea, commercial breweries would have adopted the practice. Which they haven't, and as a general principle keep in mind that if nobody's doing it, there are usually good reasons for that. :-)
Light (esp. blue)...
I believe that the short answer is yes, artificial light can cause sun damage too.
Ultra-violet light is cited as the primary spectrum/wavelength/frequency that has the biggest impact, and while direct sunlight is going to have much more of it and therefore be more detrimental over time, light bulbs generally emit a certain amount of UV too. From what I've ...
It may be a good idea to use red light in your yeast starters when you have the most cell growth. Using it in primary may over populate your batch by diverting glucose that would have gone to EtOH production to biomass production unless you use a smaller starter.
The blue light may be useful for maximizing attenuation. If blue light supplies additional ...
my 2 homebrew fermenters were getting about 30 to 40 minutes of direct sunlight at about 10 am every morning for about 6 to 7 days and the beer tastes terrible. I am now covering up my fermenters a will see how the next batch tastes.
You can wrap the whole fermentation carboy or bucket in a black plastic trash bag. It stops light and will contain any messy spills or explosions. Be sure to leave the bag open at the top so heat and gas can escape.