| Beer comes in many different flavors and is enjoyed | | | | Using high-tech equipment called time-resolved |
| by millions around the world. However, many beer | | | | electron paramagnetic resonance spectroscopy, the |
| drinkers have had the experience of tasting skunk | | | | chemists were able to explain the precise chemical |
| beer. It's not a pleasant taste and it leaves behind a | | | | reactions that occur when isohumulones undergo the |
| bitterness in your mouth. | | | | process of photodegradation. The end product is |
| Well now, a team of chemists at North Carolina | | | | what the scientists refer to as "skunky thiol," which |
| University (Chapel Hill) believe they have identified the | | | | can be compared to skunk glands that produce the |
| culprit behind skunk beer. Hops is an ingredient added | | | | foul taste and odor. |
| during the brewing process to add flavor. It also acts | | | | Beer brewing companies understand the significance |
| as a preservative against bacterial growth. When | | | | of this research. These companies are always looking |
| beer is stored in a bottle, brewers typically use a | | | | for ways to reduce costs through methods such as |
| dark colored bottle to prevent the hops from | | | | packaging beer in less expensive clear bottles. Since |
| exposure to light. The reason is because there are | | | | the taste is an important factor in driving their sales, |
| specific compounds in hops, known as isohumulones, | | | | companies need to find methods of preserving the |
| which are sensitive to light. If hops were to be | | | | flavor so that it won't lead to skunk beer. There are |
| exposed to visible or ultraviolet light, the | | | | brewing companies that are already applying these |
| isohumulones would break down and decompose | | | | techniques by adding chemically modified hops so |
| through a process known as photodegradation. It is | | | | that it would have a longer shelf-life. |
| this reaction that lead to the skunk beer odor. | | | | |
