The omentum fat is cut from the kidneys, and the kidneys with any adhering fat go into the rendering vat. The spleen, pancreas, vocal cords, trachea, and œsophagus also go into the tank.
In general it may be said that everything connected with the viscera go into the rendering tank with the following exceptions: First, that portion of the intestines which is saved for sausage casings; second, the liver and lungs; third, that part of the heart free from fat.
In the killing of small hogs, where the intestines are not of sufficient size to be suitable for sausage casings, they also go into the rendering tank. It should be stated here that the grease or lard obtained by the rendering of the above described viscera, according to the statements of the manufacturers, is used solely in the manufacture of lard oil and soap, and does not enter into the lard of commerce.
When the processes of manufacture are properly controlled by official inspection the public may be assured that this disposition of the fat obtained by the rendering of the intestinal viscera is secured.
Butchers' Lard.—A considerable quantity of lard is made for commercial purposes by the small butcher for family use, etc. This lard is made almost exclusively by rendering in the open kettle. In the country where butchering is conducted for family use the ordinary open kettle is placed over an open fire. All parts of the fat of the animal which can be easily separated and the scraps derived from trimming the animal are used for rendering. The offal and refuse of the animal are also rendered separately and the product used for soap grease. The lard made in this way is regarded as perfectly wholesome, but it is frequently dark-colored from the charring due to rendering over the open fire and by reason of using some portions of the animal, such as tendons, from which glue is made. Such lard may contain traces or even considerable quantities of glue which, however, cannot be regarded as an unwholesome product. The partially browned residues in the kettle in the country are known as "cracklings" and are used for soap grease.
Inedible Hog Fat Products.—In the shipping of hogs a great many are smothered and others die of disease or are in a condition, at the time of slaughter, which renders them unfit for human food, either by the presence of disease or otherwise. The fats are separated from dead animals of this class and are used for technical purposes such as burning oils, soap grease, etc. There are several varieties of these inedible fats of which the following are the principal:
White Grease.—This grease is made chiefly from hogs which die in transit by being smothered or from freezing. Formerly it was the custom to make white grease also from the animals which died of disease, but the manufacture of this product has been restricted by certain state laws which forbid the use of animals which die of particular diseases, such as hog cholera, from being
