Do You Know Nutrition: Rotten egg smell in beer explained

By Phylis Canion
April 10, 2012 at midnight
Updated April 9, 2012 at 11:10 p.m.

Phylis Canion

Phylis Canion

I know that food is your specialty, but I was wondering if you could tell me why a bottle of beer I opened smelled like rotten eggs?

If you leave a bottle of beer in the sunlight for longer than an hour, the sun's wavelengths will react with the hop, resin "humulone," which will then react with the sulfur containing molecules, producing isopentenyl mercaptan.

The result when you open the bottle is the smell of rotten eggs or hydrogen sulfide. One other tidbit of information about beer is that beer is best stored in an upright position whether in a can or bottle.

When beer is laid on its side for any length of time, a larger percentage of the beer is exposed to the oxygen in the container. The more oxygen it is exposed to and the longer the duration, the less flavor the beer will have.

Is it true that insect and rodent parts are actually allowed in our food? Surely not.

So sorry to say that according to Title 21, Code of Federal Regulations, Part 110.110 allows the Food and Drug Administration to establish maximum levels of natural and unavoidable defects in foods for human use that present no health hazard, according to the FDA.

Here is a sampling; ground paprika can contain an average of more than 75 insect fragments per 25 grams. Cornmeal is allowed an average of 25 or more insect fragments per 25 grams.

Popcorn - one or more rodent excreta pellets are found in one or more subsamples, and one or more rodent hairs are found in two or more subsamples, or two or more rodent hairs per pound.

Rodent hair is found in 50 percent or more of the subsamples or 20 or more gnawed grains per pound and rodent hair is found in 50 percent or more subsamples.

For a complete list of foods and the allowed levels of defects, which includes insect or rodent filth, mold, rot and insect larvae or mites, you can download the Defects Level Handbook on the FDA website.

The FDA publishes revisions as notices in the Federal Register. If you prefer a printed version of this booklet, you can send a written request to: Industry Activities Staff (HFS-565), Center for Food Safety and Applied Nutrition-FDA, 200 C St. S.W., Washington, DC, 20204. Just include a self-addressed mailing label to expedite shipment.

Thought for the week: Ever wonder why we say fat chance and slim chance to mean the same thing?

Phylis B. Canion is a doctor of naturopathic medicine and is a certified nutritional consultant, email her at This column is for nutritional information only and is not intended to treat, diagnose or cure.



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