Why beer comes in brown bottles

I received a great book, “What Einstein Told His Cook 2”, for Christmas. (I’d previously read, and enjoyed, the first book.) This is a book about food and cooking, written by a chemistry professor. I hardly need say more about why it’s an engaging read, but I will anyway. I would much rather approach cooking from the science side, where there are rules and reasons and determinism, than from the art side, where there is chaos and personal taste and approximation. These books explain the whys and hows behind common kitchen practices, very sensibly, very educationally.

Therefore, I ended up finding the section on alcohol and various drinks to be enthralling, even though I don’t drink and expected it to be pretty much irrelevant. One tidbit I took away from the chapter was an explanation for why beer always comes in (opaque) cans or dark brown bottles:

Hops are an essential ingredient in beer, and not only for the aroma and bitterness. They clarify the beer by precipitating the proteins in the wort, and they have antibiotic properties that help preserve the beer. Among the more than 150 chemical compounds that have been identified in their essential oil are chemicals (terpenes) called isohumulomes, which are light-sensitive. When struck by either visible or ultra-violet light, they break down into very active free radicals that react with sulfur in beer’s proteins to produce smelly compounds called skunky thiols, which the human senses of taste and smell are able to detect at levels of a few parts per trillion. […] Beer that has been exposed to light for as little as 20 minutes reputedly can develop a “skunky” taste. That’s why beer is packaged either in cans or in light-proof brown bottles.

It had never occurred to me to wonder why beer doesn’t come in clear plastic or glass bottles, like soda. Now I know!

1 of 2 people learned something from this entry.

  1. jim said,

    January 12, 2007 at 10:50 am

    Neat stuff. Your mention here, your book list on all consuming, and the Amazon plogs update of your “wish list” have primed my library hold queue for the next few weeks. (Thanks!)

  2. geoff said,

    January 22, 2007 at 9:05 pm

    (Learned something new!)

    I challenge this claim on the grounds that I’ve seen (and consumed) plenty of beer from clear bottles. For example, http://www.millerhighlife.com/ageverify.aspx which I like *only* for the bottle. Perhaps such beers aren’t meant to see the light of day… or perhaps the above quote requires some historical context.

  3. wkiri said,

    January 22, 2007 at 10:21 pm

    Good point, Geoff! It might be time to email the author of What Einstein Told His Cook… again. You might remember that we sent him an email a few years ago asking what the graphic on the front of the book was supposed to mean — and he actually replied. I’m on it!

  4. geoff said,

    January 25, 2007 at 11:39 am

    I broke the story here: http://menegay.org/?p=132

  5. Jim said,

    June 15, 2007 at 12:03 am

    (Knew it already.)

    Hi, I’m a different Jim than above. Geoff’s beer didn’t see sunlight. Miller is packed in glass bottles and as little as two minutes in the sun will render it undrinkable. Any clear mug of beer drank outdoors will skunk it unless you drink really fast. This doesn’t happen to wine or whiskey. My friend that works at Coors in Golden agrees. It is part of their training. The three enemies of beer are heat, light and time.

Post a Comment

I knew this already. I learned something new!