Calcium chloride, CaCl2, is a salt of calcium and chlorine. It behaves as a typical ionic halide, and is solid at room temperature. Common applications include brine for refrigeration plants, ice and dust control on roads, and desiccation. Because of its hygroscopic nature, anhydrous calcium chloride must be kept in tightly sealed, air-tight containers. Calcium chloride can be produced directly from limestone, but large amounts are also produced as a by product of the Solvay process. Calcium chloride tastes salty so in molecular gastronomy it is used mostly to make the calcium bath for Basic Spherification since it is not consumed and therefore flavor doesn't matter. For Reverse Spherification and other gels, calcium lactate or calcium lactate gluconate are preferred to obtain a better taste.
Calcium lactate is a black or white crystalline salt made by the action of lactic acid on calcium carbonate. It is used in foods (as an ingredient in baking powder) and given medicinally. Cheese crystals usually consist of calcium lactate, especially those found on the outside, on younger cheese, and on Cheddar cheese. In medicine, calcium lactate is most commonly used as an antacid and also to treat calcium deficiencies. Calcium lactate is added to sugar-free foods to prevent tooth decay. It is also added to fresh-cut fruits such as cantaloupes to keep them firm and extend their shelf life, without the bitter taste caused by calcium chloride, which can also be used for this purpose.