60 THE CANNING OF FOODS. 



tion. Solder- topped cans seldom bulge in this way for the reason 

 that they can not be sealed when too full, and, as a rule, they weigh 

 from 3 to 4 ounces less than the hand-filled cans. Overfilling also 

 necessitates a longer process, breaking up the fruit and detracting 

 from the appearance of the product In order to bring out the flavor 

 some canners add one teaspoonful of a mixture of equal parts of 

 salt and sugar, or of one part of salt to two parts of sugar, to each can. 

 This is rarely done except upon high-grade goods and must be done 

 by hand in order to insure uniformity. 



There are several types of filling machines for solder-topped cans, 

 which consist usually of a cylinder holding the quantity of tomatoes 

 necessary to fill a can and a piston to force them in. The result is 

 more or less badly broken fruit, though the contents are just as good 

 as in the hand-packed. Some of the newer machines fill the cans on 

 the principle of a collapsible tube, and the result is a decidedly better 

 appearance. In all machine filling the measure is by volume rather 

 than by weight. Cans which are filled full of whole tomatoes by hand 

 are known as " hand-packed " or " solid-packed " in distinction from 

 those filled by machine, or filled part full of whole tomatoes and 

 juice added. The adding of juice is done for two purposes, one in 

 high-grade stock to preserve the tomato whole or nearly whole, and 

 in the standard grade to complete the machine fill or to utilize the 

 entire product. In the first case the juice is taken from whole toma- 

 toes and usually condensed slightly by boiling. In the latter case it 

 is made from the trimmings and often of inferior quality. The use 

 of water in canning tomatoes is unnecessary and is an adulteration. 



Somewhat too much stress is being placed upon the quantity of 

 solid meat which will be present after draining on a quarter-inch 

 screen. A very high percentage of solid meat may mean the use of 

 a variety which is hard and inferior, or fruit which is slightly green, 

 in which event the flavor is deficient. The full, rich flavor of the 

 tomato is not developed until it is thoroughly ripe, so ripe that the 

 processing will cause a portion of the tissue to break down, and after 

 long shipments they may be badly broken. While it is desirable to 

 have a considerable proportion of the fruit whole or nearly whole, a 

 broken condition is not of itself evidence of improper methods or 

 poor quality. The cans are next run through an exhaust box, where 

 they are subjected to steam heat for from 2 to 3 minutes, after which 

 they are capped in the usual way. Tomatoes are given a process in 

 boiling water for from 35 to 55 minutes. 



Tomatoes are packed in No. 3 cans as a general rule, though they 

 are also packed in all sizes from special cans for individual service 

 on dining cars and cafes to the No. 10, or so-called gallon cans for 

 hotel trade. Some of the latter are put up unpeeled. The No. 3 , 

 comes in the regular size and in what is known as extra tall. The 



