The Science of Butter
What makes butter so great? It tastes delicious, of course. (One of the most important compounds in butter flavor is called diacetyl, which has an intense buttery aroma.) But it's also extremely versatile. Here, we break butter down into its individual elements.
Fat
By law, butter manufactured in the U.S. must have at least 80 percent fat. When making croissants, we prefer premium European butters that contain at least 82 percent and up to 86 percent fat. This fat is made of molecules called triglycerides that are composed of one molecule of glycerol attached to three molecules of fatty acids.
Water
Butter has between 13 and 19 percent water. Because butter is a water-in-oil emulsion, the water is suspended in the fat, creating a solid mass. A small amount of protein coats the water droplets and keeps them from coalescing until the butter is completely melted.
Milk Solids
About 1 percent of butter consists of milk solids, which comprise everything other than fat and water and include proteins, carbohydrates, vitamins, and minerals.
