I’ve been curious how cautious I should be about keeping my fermenters in a dark place. What does light do to a beer? I’m assuming UV is the issue here. Educate me. 
UV light reacts with acids from the hops causing that skunky smell/taste that you smell every time you open a Corona or a Heineken in a green bottle.
Agreed… Avoid sunlight and to a lesser extent fluorescent lighting(It takes longer to skunk)…But I,ve read sunlight can do it it in almost no time…Cheers Tank :cheers:
Oh the oft misunderstood concept of Skunking. Although correct above, it actually deals with the riboflavin produced by fermentation. This provides the catalyst to affect the isohumulone (from hops). This then reacts with proteins that contain sulfur. This then results in Thiol… which provides the “skunky” smell/flavor.
What’s interesting about that is that hop extracts are reduced iso-alpha acid products which help make them less prone to photodegradation, thus prohibiting this. This is why Miller can get away with using clear bottles with their Champagne of Beers.
If you are really interested in this, take a typical pale lager. Pour half in a clear cup and eave the other half in the brown bottle. Put out in sun for 15mins. Taste the bottle… then taste the glass. That’s thiol.
A side note. Incandescent light from an old fashion light bulb is much safer than sunlight or fluorescent lighting. For carboys or buckets (less likely to be light struck) a T-shirt over them helps and makes them look like guys with little heads :lol:
