The first operations in soup making are the same as in pulp. The same care must be taken in sorting and washing the tomatoes, and the government authorities put soup on the same basis as other tomato products when it comes to microscopical analysis. The fact that soup contains flour and butter makes the counting of yeasts, spores, and bacteria under the microscope a difficult operation. The molds, however, show up almost as well in soup as they do in pulp. Beginning the Cook and Adding Soda The tomatoes must be cycloned before they are converted into soup. Crushed tomatoes will not do. The cycloned juice for each batch is measured in the same manner as for catsup, and any of the types of cooking kettles that are used for catsup are satisfactory for soup. For a 100 gallon batch of finished soup, using the amount of flour I am going to recommend, about 28 or 29 bushels of tomatoes will be required. As soon as all of the tomato juice for the batch is boiling in the cooking kettle the soda is added. The amount of bicarbonate of soda to use depends upon whether the soup is being made from fresh tomatoes or pulp, and if made from pulp the soda should be varied according to the pulp’s acidity. It is nearly always necessary to use more soda in pulp than in fresh tomatoes, and if the pulp is old goods which has lost much of its sweetness, and in which the acid has been increased by the slow but telling action of living bacteria, still more soda must be used. For fresh tomatoes 18 to 20 oz. of soda is enough for a batch of 100 gallons when finished, but for pulp, as high as 30 oz. may be required. If it takes more than this to reduce the acidity of the pulp to the proper point, that pulp had better be used for some other purpose than soup. There is a limit as to the amount of soda that can be added without loss of tomato flavor. The soda is added a little at a time while the pulp or tomato juice is boiling. The cook must allow considerable room for effervescing, so that the formation of the carbonic acid gas will not cause much of the contents to be lost by flowing over the top of the kettle. Cutting the foaming tomato juice with a sharp spray from the hose will help to keep the effervescing mass down. Butter, Spices and Onions