How do beers get skunky

But what makes beer skunky? However, skunkiness in beer is caused not by heat, but by light. In fact, skunky beer is often called lightstruck beer, which sounds way cooler than it actually is. Isohumulones also known as alpha acids , the bitter compounds in hops used in beer, are very sensitive to natural light artificial light affects them, too, but not nearly as fast , which triggers a chemical reaction. Some people can detect MBT at concentrations as low as one-billionth of a gram in a ounce beer.

Canned beer offers the best protection against damaging light waves, and brown bottles rate a close second. Pilsners , traditionally bottled in green glass, are very susceptible to skunking. Serious Eats has advice on how to tell skunky from funky. Heat speeds up oxidation, and the beer begins to taste like cardboard. The resulting compounds bind with proteins that contain sulfur. People can taste this chemical in concentrations of one part per billion.

As the video explains, "if you filled an Olympic-sized swimming pool with beer, one eyedropper of this stuff would change the way it tasted.

So treat your beer with respect and keep it out of the sun, especially if the beer is in a clear glass. Supposedly, enough light can get through a green bottle to skunk it, if given enough time. Watch the full video for more. This post is part of a continuing series that answers all of your "why" questions related to science. Have your own question? Email science businessinsider. For you. World globe An icon of the world globe, indicating different international options.

Get the Insider App. Click here to learn more. A leading-edge research firm focused on digital transformation. Beers on a sunny patio. When brewers add bittering hops to their brew, it releases iso-alpha acids and makes the beer bitter as you may remember in our earlier article Hops Intro The sunlight breaks down the alpha acids to produce sulfur compounds, specifically, 3-methylbutenethiol if you want to be nerdy about it.

The reaction also occurs very quickly: 30 seconds of exposure in clear glass bottles is more than enough time to get skunky. There are a couple different ways that brewers can combat skunking. Packaging in cans rather than bottles prevents skunking entirely as light cannot pass through.