Or, since it is not always convenient to try out the scraps and strain the grease, it is quite customary to allow such grease and scraps to accumulate for a longer or shorter period. Hence another method is to have at hand a large iron kettle partly filled with weak lye and drop into this all the bits of fat from steaks, chops, and ham, surplus grease used in frying, and the like, including bits of lean meat and bone. The action of the lye partially saponifies the grease and prevents it from becoming rancid. Before the kettle becomes full, an op portunity may be taken to try out the grease by boiling and straining.
Or have at hand a half barrel or cask containing weak lye, drop into this cask all the scraps and grease, and allow them to accumulate until the time comes for soap making.
To Purify Grease.—If grease and scraps are exposed to the air at or dinary temperatures, the particles of lean meat and other impurities which they contain will decompose and the grease itself will become rancid.
When this happens, put the grease in a boiler with about three times its weight of water, and add 1 teaspoon ful of permanganate of potash for each 6 pounds of the grease. Stir, boil, and strain through a cloth, squeezing the scraps as dry as possi ble. The pot of lye can be added to the kettle of soap.
To Grain Pat.—A much better soap may be made if the accumulation of grease is prepared by a process which reduces it to a granular stale. Giained fat is sweet and is acted on by the lye easily and quickly, probably because its granular condition enables the al kali to come in contact with a greater portion of its surface. It gives a soap free from rank odors, and if thor oughly dried and kept dry may be preserved for an indefinite time.
To grain fat it must be cut into small pieces and boiled in water in the proportions of about 40 pounds of water to 100 pounds of fat. To this mixture add pound of alum and pound of salt. Boil and strain through a coarse cloth. Wash the cake of strained fat in clean water. Remelt with gentle heat, and pour into a receptacle containing about twice as much water as the melted grease. Now add about one tenth by bulk of good clear soap in comparison with the amount of grease, taking care that the temperature of the grease and water is kept at about blood heat. Stir the mixture thoroughly until cold, allow the fat to rise, and it will be found in a perfect granular condi tion. It should be placed on slats to drain, and thoroughly dried before being packed in tubs or earthenware for preservation.