16 BULLETIN 1055. U. S. DEPARTMENT OF AGRICULTURE. 



highest average score. 26.6. based on three years' tests. In the single 

 season's scores there were three varieties that were tied for highest 

 place, Flourball, American Wonder, and British Queen, all scoring 

 29.5 in 1917. The lowest average score, 12.4, was given to Switez, one 

 of the German starch varieties. This variety was not adapted for 

 chip making and was merely tried to see how it would behave. The 

 same may be said of the potato receiving the second lowest score, 17.1, 

 Wohltmann, another German variety. The lowest 1-year score was 

 given to Switez in 1916 also. 



LOSS IN PEELING AND QUANTITY OF CHIPS OBTAINED. 



Table 2 gives a 3-year average of the loss in peeling and the quan- 

 tity of chips made from all lots, with detailed figures for a few of 

 the better known commercial varieties. The average waste in peeling 

 all the potatoes handled during 1915, 1916, and 1917, a total weight 

 of 233,492 grams, averaged 12.47 per cent, and the quantity of chips 

 obtained averaged 29.85 per cent of the weight before peeling. In 

 1915 the average loss for all lots was 13.16 per cent and the average 

 weight of the chips produced was 27.43 per cent of the original 

 weight of potatoes. In 1916 the loss through peeling alone averaged 

 14.33 per cent ; through both peeling and slicing, 17.48 per cent ; and 

 the quantity of chips produced averaged 30.22 per cent of the original 

 weight. In 1917 the loss through peeling alone averaged 11.67 per 

 cent; through peeling and slicing, 16.36 per cent; and the chips 

 weighed 30.18 per cent of the original weight of potatoes. The 3- 

 year average was therefore reduced by the 1915 figures, both the 1916 

 and the 1917 averages being slightly over 30 per cent. Commercial 

 men figure on getting between 15 and 27 per cent of chips from each 

 barrel or sack of potatoes. Their percentages of waste in peeling 

 are higher than the 12.47 per cent given here, for more careful meth- 

 ods were employed in the laboratory than would be possible in a 

 large factory. Langworthy 5 estimates the average waste in peeling 

 potatoes to be 20 per cent, and with careless methods it may go even 

 higher. 



The lowest possible percentage of waste in peeling may depend upon 

 a number of factors, such as variety, place where grown, and condi- 

 tion of the tubers (i. e., firmness, freedom from injury, decay, sprouts, 

 etc.). The shape of the variety is one of the chief determining 

 factors, for when the tuber is irregular, knobby, with deep or numer- 

 ous eyes, it is practically impossible to prevent paring deeply. The 

 skin itself varies slightly, being thicker on certain varieties, especially 

 those with rough or netted exteriors. The influence of different soil 

 types and environmental conditions sometimes causes a greater vari- 



5 Langworthy, C. F. Potatoes, sweet potatoes, and other starchy roots as food. U. S. 

 Dept. Agr. Bui. 468, 29 p., 7 fig. 1917. 



