Potassium Levels in Wine

Humans need potassium to keep the muscles and nervous system healthy and to regulate the amount of water in the body's blood and tissues, according to the KidsHealth website. Likewise, grape vines need potassium for healthy growth. Winemakers also add potassium to wine at various stages in the production process. The Center for the Public Interest's Safety Summary lists all types of potassium in its "Safe" category for human consumption.

Potassium in the Growing Process

In the Western Farm Press, agricultural consultant Lowell Zelinski explains that when grapes develop, the plants need the highest potassium levels, with the first application of potassium in the spring and more throughout the growing season. According to Zelinski, the higher the yield of a particular grape variety, the more potassium the plant needs. He adds that finding the right amount of potassium to add to the soil to create a quality wine is a matter of balance and experience.

Too Much Potassium

Some wine scientists and viticulturists caution that many growers apply too much potassium to the vines. Bruce Zoecklein, head of the Enology-Grape Chemistry Group at Virginia Tech, explains that if a vine takes in too much potassium, the pH level will rise and may reduce the wine's fruit aroma and give it a soapy feel in the mouth. Zoecklein notes that shallow soils and younger vines contain more potassium, and wines in those areas or of that age may have more potassium in the grapes.

Potassium for Deacidification

In the winemaking process, potassium is added at different stages. It may be added to the grape pulp and skins, to the grape juice and to the wine itself. According to VinoEnology.com, winemakers add two types of potassium -- potassium bicarbonate and potassium carbonate -- during fermentation to improve the quality of the wine and to even out the flavor and reduce some acidity, .

You may sometimes see potassium bitartrate crystals on the cork or at the bottle of the bottle that are produced from the tartaric acid in wine. The California Wine Club says these are harmless.

Potassium to Stop Yeast Production

Home winemaker DJ Spiess, writing at Fermentarium.com, explains that winemakers add potassium sorbate at the end of the fermentation process to ensure that the yeast stops reproducing and that any other bacteria or yeasts don't contaminate the wine. Grape juice manufacturers use the same process to prevent their product from spoiling. Wine-making kits for home brewers contain packets with just the right levels of potassium sorbate for this purpose.

Potassium Levels

The U.S. Department of Agriculture's National Nutrient Database for Potassium lists red table wine as containing 131 mg of potassium for a 3.5 fl. oz. serving and white table wine containing 73 mg per serving. Both sweet and dessert wines contain 95 mg per serving. These significant amounts are similar to the potassium in a cup of frozen blueberries, containing 138 mg, or a piece of cornbread, containing 96 mg of potassium. Foods very high in potassium include dried apricots, with 401 mg for 10 halves, one banana, with 422 mg, and 1 cup of white beans with 1189 mg.