California vineyard uses high-tech chemistry to choose optimum picking time for grapes



Chemistry helps winemakers determine the best time to pick the grapes, according to research presented at the American Chemical Society national meeting in San Francisco.
Click here for more information.

SAN FRANCISCO, Sept. 10 -- A Modesto winemaker is using the latest 21st century analytical chemistry technology to supplement the time-honored practice of tasting a mouthful of grapes to determine when the fruit is ready for picking.

The winery has turned to spectroscopy and chromatography to evaluate aroma, color, taste and mouthfeel of grapes, according to Michael Cleary, senior manager of grape and wine chemistry at E & J Gallo Winery, who described the firm's Grape Assessment Program at the 232nd national meeting of the American Chemical Society, the world's largest scientific society. Annual California wine production is currently a $16.5 billion industry.

Chromatography is a laboratory process for chemically separating mixtures into their component parts. Using this process, grapes can be analyzed for their molecular makeup. Molecules indicative of aroma, taste and feel to the palate can be identified and the grapes then harvested when these molecules are at their highest concentrations, Cleary explains.

The purpose of using analytical chemistry testing, he says, is to complement historical time-consuming -- though still useful -- evaluation methods like chewing the grapes to best determine when to pick them. "It takes good grapes to make good wine and we're trying to improve our predictions of when to harvest," he says. The pharmaceutical, petroleum, food and beverage industries, and others also use technologies like chromatography to assess their products, he adds.

Cleary's presentation is one of four papers in a Chemistry of Wine symposium, to be held Sunday afternoon, Sept. 10, and sponsored by the ACS Younger Chemists Committee. The other papers deal with wine flavor chemistry, an overview of the chemistry of winemaking and the world of the winemaking consultant.

###

The American Chemical Society -- the world's largest scientific society -- is a nonprofit organization chartered by the U.S. Congress and a global leader in providing access to chemistry-related research through its multiple databases, peer-reviewed journals and scientific conferences. Its main offices are in Washington, D.C., and Columbus, Ohio.

-- Michael Bernstein

The paper on this research, YCC 002, will be presented Sunday, Sept. 10, 2:15 p.m., at the San Francisco Marriott, Pacific Room I, during the symposium, "Chemistry of Wine."

Michael Cleary is senior manager, Grape & Wine Chemistry, E. & J. Gallo Winery, Modesto, Calif.


Last reviewed: By John M. Grohol, Psy.D. on 21 Feb 2009
    Published on PsychCentral.com. All rights reserved.

 

 

Hope is the thing with feathers that perches in the soul.
-- Emily Dickinson