

10 



EXPERIMENTS ON THE SPOILAGE OF TOMATO KETCHUP. 



rubbed to a pulp. To remove very small particles and fiber, the 

 pulp may be run through a sieving machine at once; or, if ketchup 

 of the smoothest possible kind is to be made, this procedure should 

 be delayed until after the cooking. The pulp is collected in a receiv- 

 ing vat, and only such an amount should be provided in advance as 

 will keep the kettles full, as it is better to stop the tomatoes before 

 going to the washer than to have the pulp stand for some hours. 

 In common practice, however, the pulp is either sent to the cooker 

 at once, or it is allowed to stand and partially separate. If tall 

 casks are used for this separation the solids will rise to the top 

 and the clear watery portion is drawn off at the bottom, or the 

 pulp may be strained through cloth bags. The object of this sepa- 

 ration is to secure greater concentration of the solids, retain a 

 brighter color, and shorten the time of cooking. 



COOKING AND SEASONING. 



The cooking may be done in copper kettles, as shown in figure 3, 

 though these are being superseded by enamel tanks containing silver- 

 plated coils in order to secure the brightest color. By using the 



FIG. 3. A section of a kitchen showing the copper cookers. 



latter the discoloration due to the splashing of the contents against 

 the walls of the copper vessel is avoided, and economy of space is 

 secured. Whole or ground spices, or acetic acid or oil extracts of the 

 spices may be added to the pulp in such proportion as the particular 

 brand demands. The spices most used are cloves, cinnamon, mace, 

 and cayenne pepper; but paprika, pepper, mustard, cardamon, 



