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
