March, 1928] agricultural experiments 1927 17 



THE VISCOSITY OF ICE CREAM 



In the commercial manufacture of ice cream one of the most important 

 factors is the viscosity of the mix. Studies conducted by H. F. DePew 

 show that there are two kinds of viscosity, one apparent, and the other, 

 which is of the most importance, real or basic. 



The results show that both the apparent and the basic viscosities of the 

 mix are increased by: a greater concentration of solids in the mix, an 

 increase in the per cent of gelatin in the mix, a decrease in the temperature 

 of aging the mix, and homogenization. 



Homogenizing the mix at a temperature of 145° F. gave a greater 

 viscosity reading than did a temperature of 110°. The rapidity of cooHng 

 the mix did not seem to affect the viscosity. Both of these statements 

 are contrary to ideas commonly held. 



An excessive viscosity increases the time required to obtain overrun in 

 the ice cream, and decreases the amount of overrun obtained. Extremes 

 in viscosity produced a difference in the texture of the ice cream. A very 

 viscous mix produced a smoother ice cream than a very thin mix. How- 

 ever, no difference in texture could be detected in samples where the 

 difference in homogenizing pressure was 500 pounds or less. (Purnell 

 Fund.) 



TREATMENT OF WORN-OUT HAY LANDS 



An extensive series of experiments to determine the best methods of 

 rejuvenating the large areas of worn-out hay lands in the state is already 

 under way in representative sections. The studies, which are being made 

 under the supervision of Ford S. Prince and T. G. Phillips, now involve 

 three main series of plots. One of these on the Whenal farm in Greenland 

 deals with grass; another on the same farm with legumes; a third on the 

 Carter farm at Boscawen is concerned with a dairy farm rotation. These 

 experiments are of a long time nature, and the significance of the results 

 will be most evident after a series of years. 



Experiments with Grass 



This experiment was started in 1925. There are 63 plots, 12 of which 

 represent the original sod, while 51 were plowed and reseeded with a mix- 

 ture of fifteen pounds red top and four pounds timothy per acre. 



Twenty-four of these plots were manured, and twenty-seven were not. 

 On the manured plots a stand of grass was secured. Due to a lack of 

 moisture, the low fertility of the soil and somewhat to grasshopper injury, 

 very little grass lived on the unmanured plots. These were all reseeded 

 in August, 1926, and a stand was secured on all but six of the plots. These 

 six were seeded again the last of March, 1927, but no harvest was taken 

 from them. 



The average yields for the plots harvested in 1926 and 1927 show wide 

 variations, and there may be some question about their significance due 

 to a lack of uniformity in the stand of grass. The rainfall was greater in 

 1927 than in 1926, and the hay yields are consistently higher. 



On the face of the figures presented 100 pounds of nitrate of soda have 

 given an average increase for the two years of 262 pounds of hay on the 



