10 BULLETIN" 468, U. S. DEPARTMENT OF AGRICULTURE. 



When raw potatoes are fried they lose some water by evaporation 

 and may gain a considerable amount of fat. The thinner the pieces 

 the greater will be both these changes and the crisper the cooked 

 potato. Fried potato chips, as the table on page 5 shows, contain 

 only 2 per cent of water and 39.8 per cent of fat, whereas the' raw 

 tubers contain about 78 per cent of water and 0.1 per cent of fat. 



Potatoes may be prepared for the table in a great many ways, and 

 this is an advantage, as it helps to give variety to the diet. Direc- 

 tions for some of these, along with- methods of cooking other vege- 

 tables as well, have been published elsewhere. 1 When other mate- 

 rials are added to the potatoes — for example, when boiled potatoes 

 are mashed with milk and butter — the composition of the finished 

 dish will be that of plain boiled potatoes plus the nutrients in the ma- 

 terials added. Mashed potatoes differ in color and consistency accord- 

 ing to the way in which they are handled. If the cooked potato is 

 simply run through a ricer, it yields a light, white mass in which one 

 can almost distinguish the shiny starch grains. If it is pounded with 

 a masher the starch particles are crowded together so that they catch 

 the light less and look darker in color. Adding milk or butter tends 

 to make the mixture more yellow than the plain potato, but the more 

 it is beaten — that is, the more air is forced in between the parti- 

 cles — the whiter and more creamy it becomes. 



In this country the chief test of excellence is mealiness, which 

 means that when cooked potato shall form a crystallinelike mass 

 with almost distinct starch particles, This quality depends largely 

 on the proportion of starch present. If it is abundant and evenly 

 distributed throughout the tuber the cells burst open in cooking and 

 a light, flaky, uniform mass results. If the proportion of starch is 

 small in any part of the potato, water or juice is likely to replace it, 

 which will make the potato soggy when cooked. As has been stated, 

 fresh, mature tubers hold more starch than either young or long- 

 stored ones, and the inner medullary layer or core is more likely to 

 be poor in starch than the outer layer. Therefore, well-developed 

 and well-ripened tubers are more likely to be mealy when cooked than 

 are the new or watery tubers or those which have a large core with 

 many long arms branching into the outer parts of the tuber (see 

 p. 4). 



This, however, does not tell the whole story. Anyone who cares 

 for early potatoes knows that there is a quality between sogginess and 

 mealiness that is commonly described as " waxiness," and in many parts 

 of Europe this is preferred to mealiness. While mealiness depends 

 on abundant starch and sogginess on a large water content, waxiness, 

 which to some extent at least is a varietal characteristic, is attribut- 



1 V. S. Dept. Agr., Farmers' Bui. 256 (1906). 



