Well made butters can have noticeably different consistencies. In France, for example, butter from Normandy is relatively soft and favored for spreading and making sauces—Elizabeth David said, “When you get melted butter with a trout in Normandy it is difficult to believe that it is not cream”—while butter from the Charentes is firmer, and preferred for making pastries. Many dairies will often produce softer butter in the summer than they do in the winter. The consistency of butter reflects its microscopic structure, and this is strongly influenced by two factors: what the cows eat, and how the butter maker handles their milk. Feeds rich in polyunsaturated fats, especially fresh pasturage, produce softer butters; hay and grain harder ones. The butter maker also influences consistency by the rate and degree of cooling to which he subjects the cream during the aging period, and by how extensively he works the new butter. These conditions control the relative proportions of firming crystalline fat and softening globular and free fat.