22 MASS. EXPERIMENT STATION BULLETIN 404 



Tomatoes 3.00 oz. or 2 cups solidly filled 



Potatoes 3.00 oz. or 2 cups 



Carrots L75 oz. or 1 cup 



Onions 0.50 oz. or 1/2 cup 



Corn 2.25 oz. or 3/4 cup 



Celery 1.50 oz. or 1 cup 



Celery leaves or parsley C.25 oz. or 1/4 cup 



Soy flour 0.75 oz. or 1/3 cup 



Salt 3.00 oz. or 1/3 cup 



Pepper and mixed spices to suit the taste. Only a very small 

 amount is required. 



The ingredients should be well mixed before packaging. Soybean flour, in 

 addition to being an excellent source of protein and some of the vitamins, also 

 improves the consistency and body of the soup. 



' One ounce of the mixture in a pint of water makes soup enough for four average 

 servings. The ingredients in the water should be heated to boiling with stirring, 

 and allowed to stand one hour. Pieces of the proper size will rehydrate in this 

 time, and it is then necessary only to reheat and serve. Noodles, barley, or rice 

 can be added if desired. 



REHYDRATION 



Rehydration of the vegetables requires anywhere from one-half to six hours, 

 depending on the type of product, the size of pieces, and the pretreatment to 

 which the material has been subjected. In general, the longer the blanching 

 period, the more rapidly the product will rehydrate. It should be remembered 

 that a certain amount of time was required to remove the water from the fresh 

 vegetables, and a proportional amount of time is required for water to be properly 

 reabsorbed. Just enough water to cover the material should be used, and more 

 added as required. Bringing the water and product to a boil with stirring, then 

 allowing it to stand, hastens the process somewhat. After rehydration is com- 

 plete, the product is cooked as desired (only a short cook is required owing to 

 the pretreatment) in the water in which it was soaked, seasoned to taste, and is 

 then ready for serving. Rehydration time is greatly decreased by cooking in a 

 "Presto" or similar type of small pressure cooker. 



COMPARATIVE COSTS OF DEHYDRATING AND CANNING 



It is impossible to state specifically the time required for dehydrating the 

 various vegetables. This will vary with the kind of vegetable, the shape and size 

 of the pieces, and the temperature and humidity of the outside air. Snap bean 

 sections, for example, require a longer drying period than spinach or carrots, and 

 diced products a slightly longer time than slices of the same material. However, 

 over a large number of experimental runs in the small dehydrators with normal 

 tray loads of the various products, the average drying time has been found to be 

 10 hours, with variations of two hours in either direction. Fuel costs are figured 

 on this basis. 



Table 1 shows the comparative costs of dehydrating and canning vegetables 

 with gas and electricity. If is impossible to compute fuel consumption with a 

 coal or wood stove. In general the total cost per unit quantity of material pre- 

 served is lower for dehydration than for canning, the cost being greater for both 

 methods when electricity is used. Gas rates were based on those in the Greater 



