Others, while less adamant, still wonder if wines made from the grapes containing foreign genes will retain their varietal purity.

Blueberries, plums, grapes, and cherries also contain significant amounts, ranging from 5 to 12 mg/100 g. Only fresh fruit has been shown to contain significant peonidin; frozen blueberries have been shown to contain almost none.

On occasion, the winemaker may decide to leave them in if the grapes themselves contain less tannin than desired.

Since 1982, making ice wine in Germany has been governed by rules similar to those laid down for producing traditional late-harvest wines, the most important being that the frozen grapes must contain about 30 percent grape sugar.

Before harvesting can begin, it must be shown that the grapes contain at least 255 grams of sugar per litre.

Plus, apples, grapes, and cranberries all contain malic acid, which may counter gout-promoting uric acid in your body.

Some of the earliest documented studies on the process were conducted by the French scientist Louis Pasteur who noted in 1872 that grapes contained in an oxygen rich environment prior to crushing and fermentation produced wines of different flavors than grapes produced in a carbon dioxide rich environment.

A number of reports have indicated muscadine grapes may contain high concentrations of resveratrol, and that wines produced from these grapes, both red and white, may contain more than 40 mg/l, however, subsequent studies have found little or no resveratrol in different varieties of muscadine grapes.

The individual who telephoned the U.S. embassy in Santiago on March 2 told them some Chilean grapes contained cyanide.

The area's grapes contain high amounts of sugar and are used for wine production.