Butter is generally made from cream by means of churning and working. It contains somewhat over 80% fat, which is partly crystallized. The churning proceeds most easily with sour cream, at a temperature of around 15-20°C. Therefore, butter typically is a product originating from regions of temperate climate. In addition to accumulated practical experience, a good deal of science has now been incorporated in butter making, enhancing the shelf life and the quality of the product and the economy of manufacture.