Dear Mr. Wizard:

Would you recommend using water with ozone in it to sanitize brewing equipment rather than chlorine? I found a local dealer who sells an "under the sink" ozone machine that connects in-line to your existing water line. He said that the ozone would not affect the stainless steel and would dissipate after a short period of time so as not to leave a residue. Also, what do you think about passing finished beer or wine through the ozone machine and using it as a yeast filter? It seems as though the ozone would kill the ambient yeast still in the finished beer, as well as any foreign bacteria that might still be present when it's time to keg or bottle the batch.

K. Hewitt
Salina, Kansas

Mr. Wizard replies:

When ozone is bubbled through water, the water is said to be "ozonated." Ozone is a potent oxidizing compound due to its instability and it breaks down according to the following chemistry: O3 -> O2 + O· The O2 of this equation is the most common form of oxygen in the atmosphere but the O· is special and is known as free radical oxygen. Free radicals are very reactive chemical species and, among a long list of attributes, lethal to microorganisms. The lethality of free radical oxygen makes ozonation an effective method of sterilizing water, commonly used for bottled water. The free radical oxygen eventually combines with other free radical atoms to become garden-variety O2, so ozonation leaves no residual.

Ozonated water is not used in breweries as a sanitizer, although some breweries do use ozonated water to rinse bottles prior to filling. Ozonated water may work as a sanitizer for equipment, but to my knowledge this would be a new application. I would recommend using a conventional sanitizer unless you wish to pursue your idea on an experimental basis.

Coming up with new technology is exciting, but your second idea would ruin your beer. For starters, ozonation would oxidize beer to the most extreme end of the oxidation spectrum. Also, free radical oxygen initiates rancidity, the breakdown of fats and oils into fatty acids. Use ozonated water in any brewing step requiring water, if you want - there will be no harm done in mashing, and if you dilute your wort after cooling it may add a little bit of oxygen prior to fermentation. However, resist the temptation of running beer through an ozonator. Not only will this ruin your beer, it may damage the device!

Mr. Wizard, BYO's resident expert, is a leading authority in homebrewing whose identity, like the identity of all superheroes, must be kept confidential. To see more of Mr. Wizard, check out the latest issue of Brew Your Own at better homebrew shops and newsstand locations.