14 BULLETIN 468, U. S. DEPARTMENT OF AGRICULTURE. 



and is said to be what gives them their characteristic flavor. Such 

 very small quantities are not harmful, and for that matter the 

 amount which develops in sprouting or green tubers is not usually 

 dangerous; but since the flavor is very often bad, it is a good rule 

 to avoid green tubers or to cut out any green sections before cooking 

 them. 



The illness (often serious and sometimes fatal) attributed to green 

 tubers, which occasionally results after eating cooked potato salad, 

 for instance, is due, not to solanin or any other such substance, but 

 to the rapid growth in the digestive tract of harmful bacteria 

 (usually of the group called fecal bacteria) accidentally present on 

 the potato or some food served with it and conveyed to the food 

 most often by the unclean hands of some one who has handled, cooked, 

 or served it. 



SELECTION OF POTATOES FOR TABLE USE. 



Appearance, taste, and consistency are the points by which we 

 judge a cooked potato. Unfortunately, it is not always easy to tell 

 from the appearance of raw potatoes which will prove the best, but 

 there are certain marks which aid in making a choice. 



Young or new potatoes are preferable to old or stored ones. Such 

 tubers usually have a smoother skin, though they are not as mealy 

 and do not keep as well as the older ones. Very large potatoes are 

 not especially desirable, partly because it is hard to cook them 

 evenly and partly because they are often very variable in texture. 

 Smooth, regularly shaped tubers with comparatively few eyes are 

 more economical than irregular ones which can not be pared without 

 considerable waste. 



Different varieties may have distinct flavors, but the soil and 

 climate in which they are grown and the fertilizers used cause such 

 great differences in flavor that variety alone is no sure guide. The 

 freshly gathered mature tubers usually contain a large proportion of 

 mineral matters and acids, and therefore have the better flavor. 

 Tubers old enough to sprout begin to develop an acrid taste, probably 

 due in part to an increased solanin content. 



Very watery potatoes are always undesirable, because they become 

 soggy in cooking. Young tubers are more juicy than mature ones, 

 but their juice often holds so much more protein in solution that they 

 cook to the well-known waxy consistency. A good potato to be 

 mealy when cooked should feel firm when pressed in the hand. If 

 cut, it should separate crisply under the knife and be of even density 

 throughout. If the core is large and soft, it will make a soggy mass 

 full of holes in the center. 



