Shortening
Various kinds of shortening are used in the bakery.
Among the shortenings may be mentioned butter, lard, lard compound, compounds, hydrogenated fats and vegetable oils. Butter has been prepared for centuries by extracting it from the cream of milk and its manufacture does not need any explanation.
Lard is made by extracting the fatty substance from the hogs and then rendering this substance to remove the fat. After the fat is removed it is sometimes purified by blowing air through it and then filtered, after which it is passed over cold rollers so it will be chilled. From there it goes into containers and is placed in storage ready for shipment. Lard Compound is prepared by purifying vegetable oil and then adding sufficient lardstrine and lard to produce a shortening that will be plastic and solid at ordinary temperature. The government standard for lard compound states that this compound should contain at least 25% hog lard. After the lard compound had been developed, compound came into use.
Compound is prepared by mixing the proper amount of vegetable oil with sufficient stearin to make a shortening that will be plastic and solid at ordinary temperature.
Hydrogenated Fat may be obtained by hydrogenating or in other words, by adding sufficient hydrogen to a vegetable oil to saturate a portion of the unsaturated acids in the oil, thus converting the oil into a solid fat. This may be done by fully hydrogenating some vegetable oil in the presence of a catalytic agent so as to produce a very hard fat. This hard fat can now be blended with different proportions of more vegetable oil to produce fat that will have the required melting and solidifying point. It can also be done by just partially hydrogenating the oil so as to make a fat that will be plastic and solid at ordinary temperature.
The Vegetable Oils are obtained by extracting the fat from different kinds of vegetable seeds and nuts. After the oil has been extracted it is purified by placing it into tanks, treating it with some agent such as caustic soda and sulphuric acid to remove undesirable substances. After these substances have been removed it is sometimes blown by forcing air through it and is then filtered through Fuller's air to remove the remaining undesirable matter, and coloring substances. After this has been done, the oil goes to storage from where it is drawn into containers and it is then ready for shipment.
Puff Paste Shortening is used extensively in making Danish pastry, puff paste articles of various descriptions and for the replacing of butter in many kinds of coffee cakes. Most of the puff paste shortening is made from vegetable oils largely by hydrogenating cocoanut oil so the finished product will have different degrees of hardness depending upon the purpose for which it is intended.