644 FIELD AND GARDEN PRODUCTS 



readily pass through them and drying is rendered uneven. Some 

 practical growers set a stout wire screen of about 5-inch mesh at the 

 desired height above the floor and the hops emptied from the bags 

 upon this fall lightly and evenly to the floor beneath. The top is 

 then carefully leveled with a rake. 



As soon as the floor is laid the fires are started and the heat is 

 gradually brought up to the desired point. In from three to five 

 hours the hops will have become heated throughout and sufficient 

 moisture will be driven off so that the hot air will readily pass 

 through them. Until this point is reached the temperature must be 

 closely watched, as too rapid firing at first will cause the under lay- 

 ers to scorch. In sections where drying is accomplished in ten to 

 twelve hours a very common practice is to turn the hops with a 

 wooden barley fork when the lower layers are dry enough to rattle 

 when stirred. This should be done only when absolutely necessary, 

 as turning breaks and shatters the hops and a portion of the lupulin 

 is lost. Since the hops can not be turned evenly this practice hinders 

 uniform drying. 



During the course of drying sufficient ventilation must be pro- 

 vided to carry off the moisture without at the same time cooling the 

 sides of the kiln and the top of the hops enough to cause the mois- 

 ture to be deposited. Warming the air and the sides of the kiln 

 above the hops materially aids drying. In the more northerly hop 

 regions the most successful kilns are ceiled to the top, thus better 

 retaining the heat. 



The almost universal failure to recognize the harmful effects of 

 high temperature in drying has caused wide diversity in practice. 

 Temperatures of over 200 F. are not uncommon. That this is far 

 too high has been shown by experiments made in the field with hops 

 cured on various kilns at different temperatures. Aside from ruin- 

 ing the flavor by overdrying or scorching, there is a distinct loss of 

 valuable essential principles by drying at high temperatures. The 

 volatile oil, to which the aroma is largely due, is partly evaporated 

 and the lupulin is rendered inferior, since the amount of the desirable 

 soft resins becomes proportionately less as the drying temperature is 

 increased. The best temperature for drying is yet to be determined, 

 but every consideration indicates that it should be much lower than 

 that commonly employed, probably between 100 and 140 F. 

 Practical experience has shown that good drying may be accom- 

 plished with a temperature of 110 F., and the general trend of opin- 

 ion is toward the use of the lower temperatures in drying. No fixed 

 temperature, however, can be assigned as the most suitaole for dry- 

 ing, because a degree of heat which at one stage of drying would 

 probably be detrimental, at another would have no injurious effects. 

 In taking the temperature care should be used to see that the ther- 

 mometer is placed where the heat on the hops is greatest. This 

 point has been found to be just below the drying floor. During the 

 first part of the drying a thermometer below the cloth of the drying 

 floor will register higher than one placed on the floor at the bottom 

 of the hops, and one placed just above the hops will register 30 to 

 40 lower until drying is perhaps half finished or until the heat 



