PKOCESS OF MANUFACTUKE. 11 



coriander, ginger, celery, and allspice are used by some manufac- 

 turers. When whole spices are used, it is the practice to suspend 

 them in a cloth bag or a wire basket and to take them out after 

 boiling. They tend to darken the color of the ketchup, a result 

 considered undesirable by some. The ground spices are used spar- 

 ingly, with the exception of cayenne pepper. The acetic acid extracts 

 of spices are used because they are economical and give a brighter 

 red color than is obtained with the whole spice. The oil extracts 

 produce no discoloration, but they are the most expensive and give 

 an objectionable flavor. Hungarian sweet paprika is now quite 

 largely used and adds to the color as well as to the flavor. Sugar, 

 salt, and vinegar are added in such proportion as may be desired, 

 and in some brands onions and garlic are used. 



EVAPORATION AND FINISHING. 



The pulp is evaporated rapidly to such consistency as the grade 

 and price will warrant, the reduction in volume being from 40 to 60 

 per cent. This is accomplished in about forty-five minutes. The 

 cooking is not continued longer than is necessary, as each minute 

 added to the cooking darkens the finished product. 



If the pulp has been run through the sieving machine before cook- 

 ing, the batch may be drawn off into the receiving tank for bottling. 

 If the finishing be done after cooking, the pulp is run into a receiving 

 vat, finished as quickly as possible, and drawn into the tank for 

 bottling. The ketchup may be kept at a high temperature 200 to 

 206 F. in the receiving tank by means of a small steam coil, or it 

 may be drawn to the bottling machine through a steam-jacketed tube. 

 Finishing after cooking yields a slightly smoother ketchup than 

 sieving before cooking; but it necessitates handling, reduces the 

 temperature, and increases the chances of infection. 



BOTTLING. 



The bottles should be thoroughly cleaned as ketchup will not 

 keep if placed in bottles which have been merely rinsed to remove 

 the straw; if the ketchup is not to be given an after process the 

 containers should be sterilized. In the experimental work cork 

 stoppers gave the best results and these should be sterilized in a 

 paraffin bath at 250 F. 



PROCESSING. 



An after treatment or process is given to bottled goods either in 

 a water or steam bath, the important point being that the center 

 of the bottle be raised to the desired degree of heat. If the 

 ketchup is thin this can be effected quickly, but if it is thick and 

 heavy the heat penetrates the ketchup with surprising slowness. 



