Page 16 - All About History - Issue 186-19

BEER

Sloping roof
The steep pitched roof was not
decorative. Rather, it served a purpose:
to encourage a natural rising draft
of hot air through the kiln towards
a specific point. It was important for
air to circulate in such a way because it
would draw the moisture upwards and
prevent the hops from composting. .

HOP KILN Drying the hops
The picked hops would be spread
about six to 12 inches deep across
a thin, perforated wooden slatted
drying floor that was situated
directly above the furnace and
covered with a horsehair cloth.
This would allow the heat to pass
SOUTHERN ENGLAND, 1800s through the hops for more than
10 hours, allowing their moisture
content to be reduced from 80 per
op kilns were commonplace in many cent at the time of picking to as low
southern counties of England. They went as six per cent. When they were
by this term in Surrey, Herefordshire, stored after drying, the moisture
HWorcestershire and Hampshire, and by the levels would rise by another four
name oast house in Kent and Sussex. In all cases, per cent.
they operated in much the same way, allowing
locally picked green hops to be dried and then
cooled using methods of construction and design
that evolved as demand rose.
It was a finely tuned process that needed both Using the kiln
the pickers and the farmers to be in near-perfect Attached to the stowage was
synchronisation. The pickers, for instance, were one or more kilns, which is
earning money for every bushel they amassed (an where the main action in the
equivalent of 36 litres) so they needed the farmers drying process took place.
to process their hops quickly to clear space for There were many different
shapes, with some round,
more. Hop dryers, meanwhile, needed a plentiful some square and some
supply to satiate the buying appetite of brewers, rectangular – in fact, there was
who would use the dried hops to flavour and a shift after 1900 from round
preserve beer. oasts to square ones. Both
Certainly, during the hop picking season, it was worked equally well but the
important to avoid having fresh hops stuffed in latter was cheaper to build.
sacks – or pokes – for too long because it would
run the risk of them becoming ruined. Only the
most prized dried and cooled hops of the right
colour and flavour with 10 per cent moisture
would fetch the best prices. If they crumbled when Adding sulphur
rubbed after leaving the kiln, then chances are As well as using sulphur
they were ready to sell. to prevent hop mould or
As time went on, the drying technique was mildew, many brewers
refined and farmers became more familiar with would also burn sulphur
the science and the need to keep air circulating during the drying
within the kiln. When hops became more process. This would be
profitable, it led to the creation of custom-designed done during the first
buildings rather than the early adaptations of two or three hours of
barns and cottages, and these made for a more drying, allowing sulphur
dioxide to pass through
efficient process. the hops to add flavour
Indeed, more and more oast houses were and improve the colour, Lighting the fire
built during the industry’s peak between 1860 although the practice At the bottom of the kiln, in an area known as the plenum
and 1880, when more than 70,000 acres were ended up being banned chamber, there would be a fire, fuelled by coal, wood or
dedicated to the picking of hops. When hop- during the 18th century. charcoal – a good supply of which would always be on
picking became more mechanised, however, the hand very close by. Heat would rise from the furnace, with
oasts fell out of use and, by the 20th century, air drawn into the chamber via air vents on the outer wall
many of them had been demolished or converted or through an open door towards the bottom of the kiln.
for other purposes.

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