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Hops contribute flavour and bitterness to beer, but their most important role was to act as a preservative, enabling beer to keep longer and to be traded and transported. Ale, by contrast, being brewed without hops, had a shelf life of no more than a fortnight and historically it was brewed on a small scale for local consumption.
Before the mid-16th century, hops were imported to England from the Continent. The famous Graveney Boat, a vessel dated to c.AD 895 that was found under 2m of soil in the Graveney marshes near Faversham in the early 1970s, had a cargo of hops along with quern stones from the Rhine Valley. We also have records of hopped beer being imported from Hanseatic towns to London in the 14th century.
Religious refugees from Flanders and France are credited with introducing hop-growing to Kent. A 17th-century rhyme of unknown authorship claimed that ‘Hops, Reformation, bays and beer/Came to England all in one year’. Another contemporary commentator wrote that ‘hops and heresies came among us, saucy intruders into this land’. Ale brewers clearly did not like the competition: hops were branded a ‘foreign weed’ and Andrew Boorde, the author of A Dyetary of Healthe (1542), asserted that beer ‘makes a man fat’, citing the ‘faces and bellies’ of the Dutch as evidence. Despite this, there were 32 beer breweries in London in 1574 compared to 58 ale breweries, and production went from 312,000 barrels in that year to 648,690 in 1585.
A century later, writers were complaining that not enough hops were being grown in England and that Flemish hops had to be imported that were ‘nothing near so good as our own’, according to John Worlidge, author of The Mystery of Husbandry Discovered (1675). Beer was now seen as healthy: Gerard’s Herball (1636) extolled ‘the wholesomeness of beer above ale, for the hops rather make it a physical [medicinal] drink to keep the body in health [rather] than an ordinary drink for the quenching of our thirst’.
As the market for beer expanded, so too did the demand for hops, and by the 18th century there was scarcely a farm or household in Kent and East Sussex that did not have a hop garden, while in Hampshire, Surrey, Herefordshire, and Worcestershire they were known as hop yards. Hop growing was largely centred on these six counties, based on the combination of soil, climate, and the availability of charcoal for hop drying, as well as transport routes to beer consumers in the larger towns of southern England. Growers in Scotland, Wales, and Ireland all experimented with hop growing, but without lasting success.
Growing and harvesting
Hops are a labour-intensive crop requiring a number of specialist skills. The poles, wires, and strings on which the vines are trained have to be kept in good condition to bear the weight of the vines and withstand the wind. Keeping them in good repair was an important winter job, largely carried out by men working on stilts. As the vines grew, they needed tying to the wires, a job known in Kent as ‘twiddling’ that was mostly carried out by women three times a year between April and August. Manuring and weeding, and keeping the crop free of aphids and diseases, were constant requirements during the growing season.
Then, come late August, the crop would be harvested using seasonal labourers who migrated to the hop-growing regions in large numbers. This major event in the agricultural calendar started as early as the 17th century: Celia Fiennes reported on the crowds of people she encountered on the Dover Road heading out of London to pick hops in 1697. By the mid-19th century, ‘Hopper Special’ trains would carry up to 200,000 people (mainly women and children) from London Bridge to stations in Kent for the harvest, with similar migrations out of Birmingham to the hop fields of Hereford and Worcester, and from Portsmouth to Hampshire and Surrey.
This harvest tradition continued until the late 1950s, when mechanical harvesting replaced the human pickers, and when competition from imported hops saw the rapid decline of the English hop trade. According to the Royal Agricultural University in Cirencester, where researchers are looking at how to develop sustainable approaches to hop production in a bid to stop the further demise of England’s hop-growing industry, there were 3,000 hop growers and more than 77,000 acres under hops in 1870. This was the peak year for hop production, when 35,000 tonnes were harvested. Today there are just 45 growers and only 2,000 acres under hops.
Five types of oast
Freshly picked hop flowers consist of around 80 per cent water, hence they need to be dried, and as quickly as possible after harvesting to prevent rot setting in. In the 16th century, growers laid out their crops to dry in the sun, or on an upper floor without artificial heat, but Thomas Tusser, author of the verse treatise called Five Hundred Points of Good Husbandry (1573) clearly thought that drying without a kiln was risky, given the vagaries of English weather:
Some skilfully drieth their hops on a kell [kiln]
And some on a soller [solar, or attic], oft turning them well;
Kell dried will abide, foul weather or fair,
Where drying and lying in loft do despair.
Patrick Grattan, author of Oasts and Hop Kilns: a history (see ‘Further reading’ below) has identified five types of hop kiln – the term used in the west Midlands, Hampshire, and Surrey – or oast, as they are known in Sussex and Kent. What they all have in common is some form of heating, a drying floor, and ventilation.
One of the earliest to survive is the Grade II-listed oast standing in the grounds of Godwin House (also known as Little Golford), Tenterden Road, Cranbrook, in West Kent. Because much recycled timber was used in its construction, it is difficult to date, but the adjoining farmhouse dates from 1580, and there are documentary references to an oast house there in 1688. Its use for drying hops is not obvious from the outside – it looks like an ordinary shed or barn, and it is only the presence of a large fireplace that gives away its function. A cowl was added in the 19th century to vent the humid air, which originally simply escaped through the eaves or holes in the walls.
Many early kilns must have been like this – converted from existing farm buildings – but the search for better temperature control to prevent the hops from scorching led to a new generation of purpose-built kilns, dating from the mid-17th century, with raised drying floors and small conical chimneys projecting from the roof ridge. The Grade II-listed oast at Cooper’s Green, near Uckfield, East Sussex, is one surviving example.
These two types are called ‘inset kilns’, because the drying floor is set within a building that also incorporates separate areas for storing the green hops fresh from the field, for cooling the hops after drying, and for compressing and bagging the dried results. John Mills, in his Complete System of Husbandry (1767), recommended placing the kiln and drying floor at the centre of the building so that one end could be used for green hops and the other for cooling and bagging.
The third stage in the development saw the separation of the various functions into different structures. Storage, cooling, and bagging now took place in a building called the ‘stowage’, while the kilns typically clustered around one end of the rectangular stowage, or lined up along one side. At this stage, many kilns were still square, though the fourth type – the round kiln (or ‘roundel’) – became the predominant kiln type in the mid-19th century. Square and rectangular kilns returned in the 20th century, when the fifth type took the form of a large rectangular building that housed two or more kilns under one roof, the warm air being removed not by cowls but by a louvred vent running the length of the roof ridge.
All five types of kiln are found in all the main hop-growing areas, yet each region has a recognisably distinct character. In Kent and East Sussex, the round kiln, or roundel, is dominant. The hop kilns of the West Midlands are more factory-like, with their largely rectangular plans, slate roofs, and louvred vents, while the hop kilns of Hampshire and of Surrey (concentrated around Farnham) are noted for the use of chalk in their construction.
Hop drying
In all but the earliest kilns, the heat was provided by an open hearth or an enclosed stove that would burn charcoal or smokeless anthracite so as not to taint the hops with the smell of wood or coal smoke. Air was drawn in via ground-level vents, controlled by shutters or hatches, heated by the stove, and sucked up through the drying floor by the cowl or vent at the top, thus ensuring that hot moist air did not condense on the walls and fall back on to the bed of hops. The vapour had a characteristic smell, or ‘reek’, described as ‘sulphurous’, from the addition of brimstone to the kiln during drying. The sulphur was said to brighten the colour of the hops, strengthen the aroma, and aid drying by encouraging the flower cones to open.
Drying floors were constructed with a large timber main beam spanning the interior, supported on the brick outer walls. This in turn supported 12 to 16 further beams spaced at 9in (23cm) intervals, on to which wooden slats were secured, measuring 1in by 1in (25mm by 25mm), spaced at 1in to 1.5in (25mm to 38mm) intervals. Sacking cloth laid on top of the floor prevented the hops from falling through the air gaps.
Green hops arriving at the farmyard would be stored in sacks in the open air on a covered wooden stage, with plenty of ventilation to prevent mould setting in, or lifted by hoist wheel to the first floor of the stowage, adjacent to the kiln. The hops were then laid in the kiln to a depth of 6in (15cm) and dried at a temperature of 40°C to 60°C. The hops were stirred up from time to time to aerate them, and then lifted out of the kiln with a shovel or by using a ‘lifter cloth’ laid on top of the sacking on to which the hops were loaded.
The work was highly skilled: inferior hops would result from too low or too high a temperature, or by over-drying by as little as 15 minutes. The kilns operated round the clock during the six-week harvest season, and the 12 hours that it took for the moisture in the hops to be reduced to 10 per cent allowed for two drying cycles each 24 hours. This meant that each kiln had a capacity limit, and a typical 19th-century farm needed several kilns, which accounts for the clusters of circular cowl-topped kilns that are typical of 19th-century oast houses in Sussex and Kent.
The roundel
Some 8,000 oasts and hop kilns were constructed in the 19th century, and the survival of so many of them in south-eastern England (all but a handful now converted to other uses) reflects the rise of Kent and Sussex to pre-eminence as their share of national hop production grew during the latter half of the 19th century: by 1878, these counties produced 65 per cent of England’s hops. Many of these oasts are aesthetically pleasing, with steep peg-tiled roofs rising above mellow red-brick roundels topped by rotating white cowls with vanes to catch the prevailing wind, clustering around a stowage building of red brick and white painted clapboard.
The design of the roundel has been attributed to John Read (1760-1847), of Horsmonden in Kent, who began experimenting with kiln construction as early as 1790, though he did not register a patent until 1834. Based on the knowledge he gained as the manager of garden hothouses on the Smith-Marriott estate at Horsmonden, Read introduced a new method of drying the hops, using a furnace outside the kiln to supply hot air or water to a system of pipes that wound round the kiln chamber underneath the drying floor.
Roundels were better suited to the pipework than rectangular buildings; they also eliminated the ‘cold corners’ of a square drying-floor, and it was claimed that they were capable of drying twice the volume of hops compared to a square kiln of similar floor area. Hundreds of new oasts were constructed to his design – as many as 70 new builds in one year alone – though not all hop farmers had the capital to invest in a hot water system, and many used the traditional charcoal-fired internal furnace.
Aesthetics
The aesthetic appeal of a cluster of oast houses with brick and tile the colour of a robin’s breast was not lost on wealthier estate owners, who took care with the design of their oasts. The eaves were often marked by one or more courses of decorative brick-work. Bricks with blue-glazed headers were used to create diamond patterns, alternating with red-brick stretchers. Artists found them attractive subjects for landscape painting (Samuel Palmer sketched the long-gone oast that once stood next to Ightham Mote), and the appeal of several other National Trust properties in Kent and East Sussex is greatly enhanced by these handsome buildings.
Octavia Hill, one of the founders of the National Trust, donated Outridge Farm, near Brasted, to the Trust, its oast being a prominent feature of the sloping wooded hillside. Sissinghurst and Chartwell (home of Sir Winston Churchill and family) both have fine oasts, as does Bateman’s, Rudyard Kipling’s East Sussex home. The latter features in the ninth chapter of Puck of Pook’s Hill when Dan and Una go to ‘roast potatoes at the oast house’. In the darkness of the brickwork roundel, filled with a ‘sweet sleepy smell’, they hear ‘the shovels rasp on the cloth where the yellow hops lay drying above the fires’ as they listen to tales of the religious conflicts of the Tudor period.
The National Trust also owns one of only 15 traditional oasts that are still in use, built by Sir Edward Hussey on his Scotney Castle estate, which he inherited in 1894. Today, hop drying is largely carried out in industrial fan-assisted drying units, and the oast and kilns of old have nearly all been converted to other uses.
Tower Folly, Gravesend Road, Wrotham, in Kent, once part of Millars Farm, was one of the first oast houses to be converted to a home in 1903, through the somewhat clumsy insertion of windows into the kiln roof. In 1959, it was further converted to a studio for electronic music by Daphne Oram (1925-2003), co-founder of the BBC Radiophonic Workshop. Despite the challenges of domestic conversion posed by the circular plan (kitchen units, for example, have to taper towards the front), oast houses have proved popular as homes. Planning policy emphasises preservation of the exterior appearance, so most of the original interiors have gone and the hop-drying equipment rarely survives. One place where it does is Great Dixter, at Northiam in East Sussex, where the oast that was built in 1872 is open to visitors so that they can see how it worked, while exploring the influential gardens created by Christopher Lloyd (1921-2006) surrounding the house.
Further reading:
Patrick Grattan (2021) Oasts and Hop Kilns: a history (Liverpool University Press on behalf of Historic England, ISBN 978-1789622515, £39.20).
All images: Patrick Grattan, unless otherwise stated
