Calcium lactate is a less concentrated form of calcium. As a food additive, it often replaces certain salts and helps extend a product's shelf life. You can often find calcium lactate in aged cheddar, parmesan, and gouda cheese.
Winemakers use calcium lactate to increase the pH of wine, decreasing its acidity. Calcium lactate has a harmonic sour taste, but if winemakers use too much, they can impart a sauerkraut note in wine.