(Wines&Vines) - Given oxygen, stable temperatures and a supply of sugar, yeast will happily get to work powering a fermentation.

One can safely assume that at the microbial level, the yeast don’t perceive a difference between fermenting beer and wine. In California’s capital city of Sacramento, however, the state department that applies sales tax did see a difference between yeast used for brewing and yeast used for winemaking: Wine yeast was subject to sales tax while brewing yeast was not.

“It seemed very unusual how one industry would be different from another,” said Anthony Heinrich, the commercial manager of the Australian company AB Mauri Yeast.

He said more than a year ago, the company was approached by one of its larger winery clients about putting together some technical information about the importance of yeast in winemaking after the winery realized the sales tax discrepancy between industries.

The Wine Institute then picked up the challenge of convincing the California State Board of Equalization to change sales tax annotation 440.0780, which specifies selling yeast to wineries was taxable because “yeast is used in the manufacture of wine in order to bring about the fermentation process and is not used for the purpose of physically incorporating it into the wine.”

While annotation 245.1101 stipulates, “tax does not apply to the sale of viable yeast which is sold as a food for human consumption in the production of bread and malted alcoholic beverages such as beer, mead and ale.”

The difference, according to the state BOE, is that “yeast for wine is not incorporated, and thus, not consumed by humans.”

Jason Mabbett, technical sales manager of the Americas for AB Mauri, put together a detailed memo for the state that not only defined what yeast is but how crucial it is for wineries in developing wine flavor and aroma and to produce a clean wine without any off-flavors. Mabbett also detailed how through autolysis the impact of yeast goes far beyond just the reaction of converting sugar to alcohol and carbon dioxide.