Overrun.—Creamery men are much interested in the “Overrun” which means the increase from the churn over the amount of fat in the milk. For instance, if a quantity of milk containing 100 lbs. butter-fat as shown by the Babcock Test produces 114 lbs. of finished butter, the overrun is 14%. The buttermaker who gets the largest overrun by reducing the loss of butter-fat in the skim milk and the buttermilk to a minimum, keeping the percentage of water in the butter just below 16%, and yet producing high scoring butter, is considered most efficient.
Packing.—For the market, butter is packed in tubs or stone jars. Or it is molded in neat one-pound bricks and wrapped in parchment paper.
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.
Commercial Buttermilk or Cultured Milk is simply carefully soured milk. It can be made at home from fresh milk either whole or skimmed or partly skimmed. Partially skimmed milk containing from 1% to 2% butter-fat is plenty rich enough and even better for most purposes than whole milk. The essential qualities of good buttermilk depend upon the proper ripening of the cream or milk, the development of a pure “breed” of healthful bacteria in a clean field free from weeds. Such a plantation or “culture” may be grown in milk as well as in cream. Its function is to turn the sugar of milk into lactic acid under the development of pleasing flavors and whether the butter-fat is removed by the separator or by churning makes little difference. In natural buttermilk there is always a little butter-fat—at least ½%—left, mostly in the form of fine granules, too small to be retained in the butter. If the same amount of butter-fat is left in skim milk and that is ripened and churned, the product will be identically the same as natural buttermilk from ripened cream.