266 



Cultivation of the Hop Crop. 



[June 



proportionately. With such deep loads it is most important to 

 level the hops with the greatest accuracy upon the drying-floor. 



Temperature. — Substantially the same range of temperatures 

 applies for fan draught as for natural draught. There is the 

 same danger of " reeking " at the beginning if the temperature 

 rises too quickly,, but this is not quite so acute because the 

 power of the fan is equal throughout drying (as great at the 

 beginning as at the end), whereas with the open fires the draught 

 increases as the oast warms up. For this reason it is permissible 

 to start drying at a temperature 5 or 10 degrees in advance of 

 that recommended for open fire drying. That is to say a start 

 may be made at 105° instead of the recognised 100° F. for open 

 fires; but the temperature must not rise more rapidly with the 

 fan draught and the same period must elapse before 140° F. 

 is reached or misfortunes will arise in the shape of discoloured 

 hops. Again the temperature may be raised to 150° or 155° F. 

 after " feathering " to expedite the finish. Though this high 

 finishing temperature is permissible, some careful growers place 

 the maximum for fan drying at 140° or even 130° F. and by so 

 doing contend that they retain more of the volatile oils and 

 produce a softer textured sample. 



Tiiming.— Fan-dried hops can be finished without turning just 

 as hops over the open fires can be so dried, but undoubtedly 

 turning expedites the finish and provided the operation can be 

 done without undue smashing of the cones is a wise operation. 

 From the nature of the case, however, with such a depth of hops 

 on the floor it is not an easy operation. Where facilities permit, 

 a trolley constructed to run backwards and forwards on runners- 

 above the hops enables turning to be accomplished without 

 treading amongst them. 



Control of Fires.— In the case of stove kilns the fan draught 

 does not affect the combustion inside the stove, but where fan 

 draught is associated with the open fire it introduces a disturbing 

 factor because the quick draught causes the fires to burn 

 through very rapidly and so necessitates much more frequent 

 stoking and attention to ensure a steady temperature. A com- 

 mon fault with such kilns is the inadequate size of fireplaces. 

 These should preferably be 3 times the area of similar fireplaces 

 for the same kiln with natural draught; then the fires can be 

 made up to burn more slowly and regularly and if the whole 

 area of fireplace is not required it need not be used. Another 

 consequence of fan-draught with open fires is the necessity of 

 ensuring efficient mixing of the hot and cold air entering the 



