Use of Benzoate of Soda
The use of benzoate of soda in catsup permits of the use of a much smaller quantity of vinegar and sugar than is used in non-preservative goods. About 3 gallons of 100 grain vinegar to a 100–gallon batch is all that is usually used, and this only makes it necessary to use about 50 lbs. of sugar.
The benzoate of soda is added just about a minute before the batch is done.
It should be remembered that if ⅒th of 1% of benzoate of soda is being used, this percentage is by weight, and that a gallon of cold catsup weighs 9 or 9½ lbs., depending upon the amount of sugar that is used.
CHAPTER X
FINISHING, BOTTLING, STERILIZING, AND STORING THE CATSUP
The Receiving Tank and Finisher
From the cooking kettles the catsup is usually run through the finisher, and then conducted to a receiving tank, either by gravity or by pumping. If a pump is used, care should be taken that the pump parts which come in contact with the catsup are of bronze. Needless to say, enamel lined pipe should be used. The receiving tank should be either of wood, or enamel, or glass-lined steel.
Regarding the finishing of the catsup, the action on the metal screen is more severe than in pulp, and it is best to use a monel metal screen. It will usually be noticed that the frothy catsup which collects at the large end of the cone of the screen blackens quickly. This is probably due to the air, and this catsup should be scraped off into a pail as it collects, and mixed back in the cooking kettle, just giving it a minute cook. It is also very important to see that the screen fits absolutely tight, and to frequently inspect it for small cuts which are often made by pieces of tin or glass accidentally getting into the catsup.
Filling and Sealing
If the catsup is to be sterilized after bottling it is usually just run through an ordinary enamel lined pipe from the receiving tank to the filling machine, but if it is not to be given an after-sterilization a steam-jacketed pipe should be used here. This will be discussed further later in the chapter.