| Temperature, ° C. | Per cent of solids. | |||||
| 10 | 15 | 20 | 25 | 30 | 40 | |
| To be subtracted | ||||||
| 20 | 0.55 | 0.56 | 0.57 | 0.58 | 0.60 | 0.62 |
| 21 | .48 | .49 | .50 | .51 | .52 | .54 |
| 22 | .42 | .42 | .42 | .44 | .45 | .47 |
| 23 | .34 | .35 | .36 | .37 | .38 | .39 |
| 24 | .27 | .28 | .28 | .29 | .30 | .31 |
| 25 | .21 | .21 | .22 | .22 | .23 | .23 |
| 26 | .13 | .14 | .14 | .15 | .15 | .16 |
| 27 | .07 | .07 | .07 | .07 | .08 | .08 |
| To be added | ||||||
| 29 | 0.07 | 0.07 | 0.07 | 0.07 | 0.08 | 0.08 |
| 30 | .13 | .14 | .14 | .14 | .15 | .15 |
| 31 | .21 | .21 | .22 | .22 | .23 | .23 |
| 32 | .27 | .28 | .28 | .29 | .30 | .31 |
| 33 | .34 | .35 | .36 | .37 | .38 | .39 |
| 34 | .42 | .42 | .43 | .44 | .45 | .47 |
| 35 | .48 | .49 | .50 | .51 | .52 | .54 |
Whether or not ketchup should be processed after filling into bottles depends on the conditions under which it is bottled. If the bottled product can be sealed at 180° F. or better a process is not necessary and is an unnecessary expense and waste of time, besides it may injure the color of the product. With the modern type of equipment it is possible to fill the bottles at a temperature which obviates sterilization. Care must be taken that the temperature of the ketchup in the receiving tank feeding the filler does not fall too low. Care must also be avoided in order not to fill the ketchup at too high a temperature as it results in excessive shrinkage of the contents.
For ketchup filled at relatively low temperature a process should be used. The process necessary will depend upon the temperature at which the ketchup is filled and on the time that may elapse between filling and processing. Sanitary conditions of the factory and equipment are exceedingly important not only in relation to ease of sterilization but also in securing a product of good quality.
In stacking ketchup it is best to stack the bottles upside down. This tends to prevent darkening of the ketchup in the neck of bottle, a condition known as “black neck.” It has been our experience that wherever this condition has occurred it is due to leakage of air into the bottles. Stacking bottles in this way undoubtedly keeps the cork of the cap moist and makes the seal more effective.
CHILI SAUCE
Chili sauce is of the same general character as ketchup but is made from peeled and cored tomatoes without removing the seeds, contains more sugar and onions and sometimes is made hotter than ketchup by the use of more cayenne pepper. There is a great variation among different manufacturers with respect to the methods of treating the tomatoes. Usually large to medium sized tomatoes are employed, separated from the small tomatoes which are used for making pulp and ketchup. Some manufacturers of chili sauce place the peeled and cored tomatoes directly into the kettle and mix the other ingredients without any form of breaking. Other manufacturers have various methods of breaking and crushing the tomatoes. Several crushers for this purpose are on the market and other means of breaking, such as meat choppers, meat cutters and apple graters are employed. Some convey the tomatoes from the peeling room to the kettle through a pump which breaks them up more or less.
Because of the nature of the product there is no method available for testing the concentration of chili sauce and determining the point at which the cooking should be stopped. The refractometer may be used as a rough method of controlling the concentration. The percentage of solids as determined from the refractometer reading and Geerlig’s table is too low on account of the relatively high percentage of insoluble solids. However, a relation between the soluble solids and total solids may be obtained in this way which may be useful in controlling the concentration. The consistency of the product is always regulated by its appearance. The amount of cooking varies among different manufacturers but in general there is a concentration of from 40 to 45 per cent of the volume of the raw tomatoes employed. That is, 100 gallons of peeled and cored tomatoes yield from 40 to 45 gallons of chili sauce.
The amount of onions added to chili sauce is substantially larger than the amount used with ketchup. Some manufacturers use approximately twice as much as the former. Hier[22] suggests 100 pounds of onions when used in the preparation of 100 gallons of chili sauce. Large onions should be used since they are more easily peeled and give less waste than smaller onions. They should be carefully peeled and should be finally chopped in order to safeguard against stopping up the tubes of the filling machine.
The cooking is substantially the same as with ketchup and the same ingredients are used with the exception of garlic which is not employed. Some manufacturers make the product rather mild, while others use substantially twice as much cayenne pepper as with ketchup. The same amount of salt and vinegar are employed with ketchup but substantially more sugar, some manufacturers using one-half more sugar than with ketchup.
Because of its lumpy condition chili sauce affords more difficulty in filling into the bottle than is the case with ketchup. The bottle is also harder to seal. Its wide neck makes it more difficult to make the sealing tight than the smaller neck ketchup bottles, and the black rings in the top of the bottle are more frequent and more conspicuous than is the case with ketchup.