Careful Cellaring, Part 3: The Threat of Light

Another factor that can be damaging to you beer cellar is light. Did you know a beer's flavor can change in minutes in direct sunlight? Even unnatural, fluorescent light can harm your beer. The reason this happens is because the hops in beer are very sensitive to UV light. To explain what happens to the chemistry of beer, we turn again to Jess from our lab. 

Ever wonder why "lite" beers in clear bottles taste better with a lime slice and are skunky without one? It's because of a little nasty compound called MBT or as the organic chemist might say 3-methylbut-2-ene-1-thiol.

The odor and flavor of this compound is often reminiscent of skunks but is commonly referred to as the smell and taste of a "lightstruck" beer. The chemistry that goes on to change your delicious hops to skunkiness is well known and shown in the following graph about "The Lightstruck Reaction" (Graham, 2006):