What is light struck beer?

But its alternate name, “light-struck” beer, hints at the true cause. As the name suggests, the phenomenon occurs when light-sensitive hops — a major beer ingredient that acts as a preservative and adds flavor — is exposed to too much light. Brewers have documented the problem since at least 1875.

How long does it take for beer to get light struck?

It has been said that clear bottled beer can become light-struck in less than one minute in bright sun, after a few hours in diffuse daylight, and in a few days under normal fluorescent lighting.

What happens when beer is exposed to light?

But if beer is exposed to sunlight, the sun’s power breaks down those iso-alpha acids. The resulting compounds bind with proteins that contain sulfur. This creates a new chemical — one that’s almost exactly identical to the one released by skunks. American Chemical Society/Reactions It’s incredibly potent too.

Why does light hurt beer?

Light is not going to cause wort to go skunky, but can cause this problem with beer. This is because the light wavelengths that cause beer to skunk fall between about 350 and 550 nanometers; 350 nm is the upper end of the ultraviolet range (invisible to the human eye) and 550 nm is in the visible range.

How is the flavor of light struck Beer formed?

The light-struck flavor is formed, just as the name implies, through a photochemical reaction triggered by light with wavelengths in the 350–500 nm range, which spans the blue to the near-ultraviolet portion of the electromagnetic spectrum.

Why is skunky beer called lightstruck beer?

A skunky beer is called “lightstruck” by chemists and beer nerds, and this is why you’ll often find odoriferous brews in clear or green bottles. Brown bottles block much more light and are a far superior vessel for beer, and cans (and kegs) are even better at protecting against UV exposure.

Why does brown glass keep beer from skunking?

Brown glass transmits less visible light than the previously mentioned colors, and therefore offers some protection from skunking. It does allow some light through, so beer in brown bottles will skunk after a few hours of light exposure.

What kind of light do you need to skunk beer?

The skunking process is very robust and very quick, but everything depends on whether the beer is exposed to light. Clear glass bottles let through pretty much all the UV and blue-light rays so beers in clear glass bottles exposed to light will skunk quickly. Even the lights from the refrigerator will do. Sunlight is, of course, the worst.