This section is from the book "The Orange Judd Cook Book", by Adeline O. Goessling. Also available from Amazon: The Orange Judd Cook Book.
There are all kinds of doughnuts-good, bad, and indifferent. When they are not as good as they should be, it rests with the cook, who has probably failed to inform herself on all the fine points of doughnut manufacture. The following hints may be found useful in following the various recipes presented herewith. The dough should be as soft as possible, and not handled any more than is absolutely necessary. If too much baking powder is used the doughnuts will soak up fat, and if the dough is too stiff the fried cakes will be tough. Since they are fried in grease it is not advisable to use much shortening in the doughnuts. Equal parts of clarified lard and suet are the best to fry them in. The kettle should not be too small and there should be plenty of the fat, which should be hot. To keep the fat clear and to keep it from over-heating, some cooks drop in a piece of raw potato. It is well to test with a sample doughnut, to see if the dough is of the right consistency and the fat at the proper degree of heat. When the doughnut is dropped into the fat it should come to the top almost immediately, and when it is brown on one side it should be turned to brown on the other side. When the doughnuts are lifted from the fat they should be laid out on brown paper, to absorb the superfluous fat. It is best not to fry more than five or six doughnuts at a time, as dropping in too many fresh doughnuts would cool the fat too rapidly. A little practice and careful following of directions should result in a product that is both wholesome and palatable.
 
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