=Sweet Butter.=—Real “sweet” butter is churned from fresh, sweet, unsoured cream. But usually the name is given to the _unsalted_ and _uncolored_ butter that many people relish. Without the salt it does not keep as well as ordinary butter, and must be eaten quite fresh. Well-made salted butter will keep for months with ordinary care, and in cold storage it may be kept a year. But when it comes out of cold storage it must be used within a few weeks, for butter, like other cold storage foods, will soon spoil and become rancid when it is exposed to a higher temperature for any length of time. =Renovated Butter.=—Butter that has become old and rancid can be “renovated.” The butter is melted and the butter-oil washed,—aërated in the renovating plants,—and then churned with fine-flavored sour skim milk. From the sour skim milk it gets back its old butter flavor. The granular physical consistency of fresh butter is gained by pouring the emulsified mixture over cracked ice or into ice water. By the time the excess of “buttermilk” has been removed by working, and salt has been mixed in, the renovated butter may be almost as good as fresh creamery butter. =Oleomargarine= or =Butterine= is made in much the same way. A mixture of beef-fat (the soft part of beef-tallow) and lard and cottonseed oil is churned with sour milk and worked and granulated like renovated butter. For the better grades, some of the finest creamery butter is mixed with it, so that the mixture can hardly be distinguished from real butter. =Coco-butter=, =Nut-butter=, etc., in great variety, are now also on the market as substitutes for butter, all prepared in a similar way, but lacking the vital unknown element that makes genuine butter so superior to substitutes. BUTTERMILK If the cream has been carefully ripened, with or without a pure culture starter, and it has shown the proper sourness when churned, the buttermilk will be of a pleasing taste and flavor. Its thickness will of course depend upon the amount of water, if any, added to the cream in the churn during the buttermaking. If the buttermilk is to be used for human food care must be taken not to dilute it too much. =Cooling Essential.=—If buttermilk is left to stand for hours in a warm room, fermentation goes on and may soon spoil the buttermilk by making it sloppy or bitter. It should therefore be cooled at once when drawn from the churn; if kept in ice water it may remain in fine flavor for several days. Well taken care of it is not only a pleasing and refreshing drink but eminently healthful. In cooking, too, it can be used to advantage.