14(5 



Cultivation of the Hop Crop. 



[May, 



must handle the hops, or alternatively leave them a length of 

 time which experience may indicate to be correct. 



Another common mistake is to open not only the shutters and 

 doors below the hops but those above the drying floor as well; 

 by such practice the air above the hops only is cooled, but since 

 the cool air entering above the hops does not pass through them, 

 the hops themselves are not cooled. This sounds very obvious, 

 but the mistake is very frequent in the oast. 



Control of Fires. — The work of the hop drier is made con- 

 siderably less anxious if his kilns are fitted with large enough 

 fireplaces; if these are greater than required he is not obliged to 

 utilise the whole of the fire bars, but if too small they may have 

 to burn too fiercely and constantly need attention. This fault 

 is particularly likely to arise when hops are dried over open fires 

 with fan draught. Wherever fires are liable to burn fiercely, or 

 the fireplaces are nearer than usual to the drying floor a baffle 

 plate should be suspended above them to prevent heat being 

 directly radiated from the fires to the cloth, in which case the 

 hops are liable to be burnt. It may be noted in passing that 

 this radiated heat is very different in its properties from heat 

 carried by warm air; the former " strikes " one's face when 

 sitting before a blazing fire, the latter is produced when hot 

 water pipes are used to warm a room. In hop drying radiated 

 heat is dangerous and must be prevented from acting; it is the 

 current of warm air passing through the fire by means of which 

 the hops are dried. 



At the beginning of drying and as soon as the hops have been 

 loaded the fires are made up with large lumps of coal so that 

 they will burn slowly and steadily for 4 or 5 hours, gradually 

 gaining in heat as the hops begin to dry and the draught con- 

 sequently improves. Should the temperature tend to rise too 

 rapidly the fires are checked not by damping them with ashes 

 but by raising the blowers to admit more cold air to the kiln and 

 by this admission of air check the draught through the fire. So, 

 too, if the fires want lifting after restoking or because they tend 

 to deaden, this should be done by increasing the draught through 

 the fires by partially closing blowers. Some driers use large 

 quantities of charcoal for the purpose of raising their fires ; this 

 is costly and unnecessary except when the fire is very dead when 

 made up. 



The stoking of the fires during the latter part of drying calls 

 for much less skill than at the outset ; the only precautions 

 necessary are to avoid great fluctuations in temperature and to 



