Harvest brings a busy season to wineries

Since early September, wineries in California and throughout the Northern Hemisphere have been engaged in their most critical tasks of the year.  The decisions they make during this busy period of four to eight weeks will play an important role in how their wines will perform when released to the public a year from now, in the case of many white wines, and up to four years from now for full-bodied red wines.
While temperatures rose in spring and summer, grapes became sweeter, while their acidity and tartness decreased. In August, winemakers checked the level of sugar in the grapes at least once a day, waiting for the optimum time to take grapes from the vines and begin the winemaking process.
Picking grapes early will mean a little higher acidity in the wine and a lower alcohol level. However, if picked too soon, some unwanted flavors and off-odors could end up in the final wine.  Wait too long to pull the grapes and the winemaker runs the risk of fermenting overripe grapes that leave too high a level of residual sugar in the wine, or produce too high a level of alcohol, creating an unbalanced wine.
In addition to checking the sweetness in the grapes, the phenolic compounds must also be mature enough for picking. These are the chemical compounds that produce the wine components of color, tannin and flavor.
Once picked, red wine grapes are separated from their stems and gently crushed in order to release the juice. For white wines, the grapes are not crushed, but pressed with the stems still intact so that the juice from the grapes can be immediately separated from contact with the skins and pumped into a fermenting vat.
A fermenting tank will be filled about three-fourths to the top to allow room for carbon dioxide gas to be released from the juice. The temperature of the wine will naturally rise during fermentation and it is critical that the temperature range be controlled carefully. If left to rise too high, the wine will end up with an unpleasant, burnt flavor.
Once the primary fermentation of red wine ends, and more juice is squeezed from the skins through a process called pressing, the juice will be transferred to another vat, or barrel. With each transfer like this, called “racking,” the wine becomes clearer. Most red wines will settle down in barrels for a period of eight to 24 months before being bottled and released to the public.

Len Napolitano lives in Central Coast wine country and is certified in wine by the Society of Wine Educators, Wine & Spirits Education Trust, and Chicago Wine School and continually gains knowledge from his frequent contact with California winemakers. More information is on his website, www.wineology.com . Send your questions about wine to: wineologist@earthlink.net or by mail to Len Napolitano in care of Wine Country This Week magazine. Wineology is a registered trademark of Len Napolitano.com