Human cells rely on the right balance of potassium both inside and outside, and a correct balance promotes normal nerve, muscle and heart function. While fruits and vegetables are among the top sources of potassium, wine, including red and white, supplies small amounts of potassium, as well.
Where the Potassium Comes From
Much of the potassium in wine comes from the potassium in the soil where grapevines are grown. As the vines grow, they absorb the potassium in the soil. In fact, many grape farmers add potassium to the soil because it can produce a larger crop of wine grapes. The potassium sorbate used to preserve certain types of wine can increase the potassium content a bit as well, according to the University of Minnesota.
Decreases in Potassium Content
The wine-making process directly influences how much of the potassium is retained in the alcoholic beverage. Certain processes, such as ion exchange in which potassium is exchanged for sodium, decreases the amount of potassium in the beverage, according to Ronald S. Jackson, author of "Wine Science: Principles and Applications." Removing potassium ions helps prevent crystallization, Jackson notes.
Potassium in Red Wine
A 5-ounce glass of the average red table wine contains 187 milligrams of potassium. That translates to about 4 percent of the 4,700 milligrams potassium healthy adults need daily. The same amount of Merlot also contains 187 milligrams of potassium. The skins of grapes aren't removed when making red wines, which is one contributor to the potassium levels. Red sweet wines contain slightly less potassium than traditional red wines.
Potassium in White Wine
A 5-ounce serving of the average white table wine contains less potassium than red wine with 104 milligrams, or 2 percent of the daily 4,700-milligram recommendation for adults. The same amount of Chardonnay also contains 104 milligrams of potassium, and a white sweet dessert wine contains 135 milligrams per serving. White wine can be processed differently than red wine, which is one reason the potassium level in white wines is lower. Many white wines are chilled, and the chilling process can influence potassium, too, according to Jackson.