Wine 101

You’ve navigated the state – now try the vineyard, the winery and the cellar! Making your way around the California wine world is much easier when you know the basics.

/ Winegrowing

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/ Fun Facts

/ Winemaking

Harvest in California usually begins in late August to early September and may last through November, depending on the weather and the grapes.
After harvest, grapes are placed in a destemmer/crusher, which separates the stems from the fruit and breaks up the berries. The stems are then discarded leaving the "must," a combination of juice, seeds, pulp and skins. Grape skins are what give red wine its color, flavor and “tannins” – the polyphenols that enable red wines to take on more complexity as they age. During white winemaking, skins and seeds spend only a few hours with the juice, known as "free-run." The skins are then pressed to extract all the remaining juice, called "press juice." The free-run and press juice are then filtered in preparation for fermentation.
Yeast is added to the juice to begin fermentation, the process by which the natural sugars convert to alcohol. Wines may be fermented or aged in oak or stainless steel barrels, or both. Sometimes a second fermentation, called “malolactic,” is initiated to convert the tart malic acid found in fruit to softer lactic acid. Fermentation lasts anywhere from three days to three weeks, depending on the wine.
Wines can be aged in stainless steel or oak barrels. It is common for red wines to be aged in oak barrels for one to two years. White wine is aged anywhere from one week to a year. Sparkling wines made in the method champenoise may be bottled and cellared for two years or more. After aging, the wine may be blended with other wines to add different characteristics or create the desired style.
Finally the wine undergoes finishing, a process by which the wine is stabilized and filtered before bottling. Egg whites or gelatin are added to remove astringent substances or proteins which can cloud the wine and give it off flavors. Sulfites may also be added to prevent oxidation and bacterial spoilage.
Sparkling wines are made from white and red still wines. After choosing a base varietal or blend, the winemaker mixes up a “tirage,” which includes some of the base wine plus yeast and sugar. The tirage is then added to the rest of the base wine, causing the entire mixture to ferment again – this time in a sealed container. As the sugars convert to alcohol, carbon dioxide is trapped inside, producing the finished wine’s effervescence.

/ Fun Facts

  • Millon people visit california wine country each year
  • 85% of the wine made in united states comes from california
  • No. 4 wine producer in the world, after france, italy and spain

/ Conversion Chart

Celsius (C) = 5/9(F-32) | Fahrenheit (F) = 9/5(C+32)
1 inch = 2.54 centimeters
1 foot (12 inches) = 30.48 centimeters
1 yard (3 feet) = 91.44 centimeters
1 mile = 1.61 kilometers
1 kilometer = 0.62 miles
1 hectare = 2.471 acres
1 acre = 0.405 hectares
1 liter = 0.264 gallons
1 gallon = 3.785 liters
1 hectoliter = 26.417 gallons
Vineyard Yield
1 ton / acre = 15 hectoliters / hectare
(this is an estimated average and depends on vine density)
1 kilo = 2.205 pounds
1 pound = 454 grams

How to read
a wine label

See details

/ How to read a wine label

California winery Zinfandel Napa Valley California Vaniyards Vintage Year


This is the name chosen by the producer. Names can reflect a place, brand concept or the producer’s surname.

Type of wine

This may be a varietal, generic or proprietary name. Varietal wines must be made from at least 75% of the stated grape variety.

Place of origin

For a wine to carry an American Viticultural Area (AVA) name on its label, at least 85% of the grapes must be grown in that AVA. If a wine label uses a county name as an appellation, then at least 75% of the grapes must come from that county. A wine bearing "California" ensures consumers that 100% of the grapes were grown in the Golden State.


When a vineyard is listed on a California wine label, it indicates that 95% of the grapes came from that vineyard.

Vintage Year

This is the year the grapes were grown. Wines must contain at least 95% of the stated vintage if the appellation is an AVA, and at least 85% for appellations that are a county or state. With California’s temperate and reliable climate, every year is a good year.