English School 19th, Century
Labourers Hop Picking on a Hop Farm, Kent
Labourers Hop Picking on a Hop Farm, Kent
oil on canvas
45 x 59 cm. (18 x 24 in.)


The first documented link between hops and brewing comes from Picardy in Northern France, in 822, where Abbot Adalhard of the Benedictine monastery of Corbie, in the Somme valley near Amiens, wrote a series of statutes on how the abbey should be run. The many rules covered areas such as the duties of the abbey’s tenants, which included gathering of firewood and also of hops – implying wild hops, rather than cultivated ones. Adalhard also said that a tithe (or tenth) of all the malt that came in should be given to the porter of the monastery, and the same with the hops. If this did not supply enough hops, the porter should take steps to get more from elsewhere to make sufficient beer for himself: “De humlone … decima ei portio … detur. Si hoc ei non sufficit, ipse … sibi adquirat unde ad cervisas suas faciendas sufficienter habeat.”

It is important that the Corbie statutes should link hops with beer brewing, because hops had other uses they might have been collected for: to make dyes, for example (brown dye from hop sap and yellow dye from the leaves and cones). The stems can also be used to make ropes, sacking and paper. Thus any mentions in old documents of hops being collected from the wild, or even cultivated, does not mean automatically that the hops were going into beer

But Adalhard’s statutes do not say whether the hops were being used to preserve the beer, or merely to flavour it (the way brewers today dry-hop their beers). Proof that hops were being used the way they are today, as a preservative, does not come for three more centuries, at another Benedictine establishment at Rupertsberg, near Bingen, in the Rhineland. About 1150, Abbess Hildegard of Bingen (1098-1179), mystical philosopher and healer, published a book called Physica Sacra, which translates best as “The Natural World”. Book I, Chapter 61, “De Hoppho”, or “Concerning the hop”, says of the plant: “It is warm and dry, and has a moderate moisture, and is not very useful in benefiting man, because it makes melancholy grow in man and makes the soul of man sad, and weighs down his inner organs. But yet as a result of its own bitterness it keeps some putrefactions from drinks, to which it may be added, so that they may last so much longer.”

By itself this does not prove hops were used in beer, just “in drinks” (in potibus in Hildegard’s original Latin). But in a later chapter, on the ash tree, the abbess wrote: “If you also wish to make beer from oats without hops, but just with grusz [gruit], you should boil it after adding a very large number of ash leaves. That type of beer purges the stomach of the drinker, and renders his heart [literally ‘chest’ or ‘breast’] light and joyous.” Clearly Hildegard knew about brewing beer with hops. The passage also suggests that Hildegard knew about boiling wort, without which just adding hops is not much help in keeping away “putrefactions”.

What probably kept the usefulness of hops from being discovered for so long is that the bittering, preserving resins in hop cones are not very soluble, and the hops need boiling for a long time, around 90 minutes, for what is called isomerisation – the physical change in the hop acids to a more soluble form of the molecule – to take place. Nobody would have boiled hops that long, and thus discovered the isomerisation, without a prior good reason (it takes a lot of fuel, a precious commodity when you have to gather wood by hand, to boil quantities of water for an hour and a half). How was it found out that a good long boil improved both the flavouring and the preserving ability of hops? One possibility is that a dyer, boiling hops to dye cloth, made the discovery that the dye water had a pleasant bitter taste, and told her friend the brewer. But this is just a guess.

When exactly hops began to be cultivated for putting into beer, rather than just being gathered wild from forests, is surprisingly unclear. German sources today claim that hop gardens appear in records dating from the second half of the ninth century in and around Hallertau, in Bavaria, Southern Germany, which is still the world’s largest single hop-growing area. However, they do not specify exact documents in which these hop gardens are mentioned, which makes it impossible to rely on their assertions. The best evidence seems to be that commercial hop cultivation happened in Northern Germany first, and not until the 1100s or 1200s, feeding the breweries of the Hansa trading towns, which were exporting hopped beer from at least the 13th century onwards. (Merchant beer brewers in North German cities eventually became rich enough to join the local aristocracy, something not found in Britain until the 18th century).

The buyers of this beer brewed in cities such as Hamburg and Bremen included the richer inhabitants of Flanders and Holland. Local brewers in the Low Countries reacted by brewing hopped beer themselves, and by the 1360s or thereabouts Dutch towns were growing hops to supply their brewers. From around 1390 brewing of hopped beer took off in Holland, with Flanders following a decade or so later.

The first import of Low Countries “beere” into England seems to have come in 1362/63, when James Dodynessone of Amsterdam paid a toll on beer at Great Yarmouth in 1361-62. (There is a reference in the Norwich Leet Roll of 1288-9 to cervesiam flandrensem, or Flanders ale, which “Ricardo Somer”, Richard Summer, was fined 2s for selling occulte, secretly, thus depriving the bailiffs of money due on the ale of ale. However, this was probably too early to be a hopped brew). Further mentions of beer imports followed, gradually increasing in frequency: Henry Vandale (a man with a Dutch-sounding surname) bought four barrels of “beere” in London in 1372. A ship’s captain named Clays Johanson arrived in London in July 1384 with a cargo that included earthenware dishes, Holland linen cloth and beer. Other records of beer imports in the late 14th century come from Newcastle, Scarborough, Lynn, Ipswich, Winchelsea and Sussex. At the end of the 14th century Great Yarmouth was importing 40 to 80 barrels of beer a month, while in 1397-8 Colchester imported 100 barrels of beer.

However, the first brewer of the hopped drink in England does not appear until 1412, when Agnes Smyth, “Dutchman” (sic – and “Dutch” meant “German” at this time, rather than “person from the Netherlands”), was making beer in Colchester. The English beer trade seems to have stayed in the hands of immigrants from the Low Countries for the next century, as the conservative-minded natives stuck to their unhopped ale. As a result, the first beer brewers in England apparently imported all their hops from across the Channel, with no attempt to cultivate the plant here until early in the 16th century.

When exactly the first hops were grown in England is, again, uncertain – dates given by different writers range from 1511 to 1524. But the place where they were first planted was almost certainly Kent: one tradition says the first hop garden was established in 1520, in the parish of Westbere, near Canterbury. By 1569 English hop cultivation was sufficiently advanced for one agricultural writer, the Sussex landowner Leonard Mascall (or Mascal), to claim that “one pound of our hoppes dried and ordered will go as far as two poundes of the best hoppe that come from overseas.”

Five years later, in 1574 the first book in English solely devoted to hop growing was written by a 36-year-old Kentish landowner called Reynolde (or Reginald) Scot. His A Perfite Platform of a Hoppe Garden, filled with woodcut illustrations to aid the less literate Elizabethan farmer, went to three editions in four years. By 1577 hop cultivation had reached Herefordshire, where a “hoppyarde” was running at Whitbourne, near Bromyard. The differences found in the terminology used between the West Midlands and South East England – hop yard for hop garden, hop kiln for oast house, crib rather than bin for the container the hops are picked into, for example – suggest hop-growing was started independently in the two places.

In 1655 hops were being grown in at least 14 English counties, including Somerset, though Kent accounted for a third of the total crop. The use of bitter hop alternatives such as broom and wormwood was banned by Parliament in 1710 to ensure brewers did not try to avoid the new hop tax of a penny a pound. However, although it was reckoned an acre of hops would bring in more profit than 50 acres of arable land in a good year, the hop farmer’s life was more insecure than any other branch of agriculture. An old Kentish rhyme said of hops: “First the flea, then the fly/Then the mould, then they die.” Annual yields swung wildly: 1.57 million pounds of hops in 1726, for example, 20.39 million pounds the following year.

John Banister of Horton Kirby in Kent, in a book called Synopsis of Husbandry, published in 1799, identified a long list of different types of hop, including “the Flemish, the Canterbury, the Goldings, the Farnham etc.” Goldings is still regarded as one of the great English hops, though it now comes in several varieties: it was supposedly propagated from an especially fine plant spotted not long before 1790 by Mr Golding of Malling, who was still alive in 1798.

Stourbridge fair, just south of Cambridge, was the biggest hop mart in England in the late 17th and early 18th century. By the late 18th century Southwark, in London, which was handily placed on the road up from Canterbury, had become the country’s most important hop centre. (When “three-letter” telephone exchange names were introduced in London before the First World War, Southwark’s was HOP – even today, many Southwark telephone numbers still contain the numerical equivalent, 407.)There were 35,000 acres of hops under cultivation in Britain by 1800, and 50,000 by 1850. Hop farming hit a peak of 71,789 acres in 1878, with hops grown in 40 English counties, though the tiny Scottish hop industry, which operated in just five counties, disappeared in 1871, and Welsh hop growing ended in 1874. Hops from Farnham in Surrey were regarded as the finest, followed by Kentish hops, though some brewers paid a premium for North-Clay hops grown on the stiff clays of Nottinghamshire, which were reckoned to be the best for strong keeping-beers.

New varieties of hop were still appearing: Bramling, an “early” variety of Goldings, named after the hamlet near Canterbury where it was discovered, was introduced about 1865. According to later writers, Richard Fuggle of Brenchley, Kent unveiled the hop variety that still bears his name, the second great English hop, in 1875, though this has since been thrown into doubt. The first Fuggles plant supposedly originated from a seed thrown out with the crumbs of a hop-picker’s lunch at George Stace’s farm in Horsmonden, Kent in 1861. A book on English hops published in 1919 listed more than 30 different hop types. However, tastes were changing away towards sweeter, less-hopped milds, and at the same time imports of hops from Europe and the United States were increasing. total hop acreage plunged to 51,000 in 1900, a drop of almost 30 per cent in 22 years. The restrictions on brewing of the First World War also hit the industry, and by 1918 there were just 16,000 acres under cultivation.

At the beginning of the 20th century it was realised that the soft resin content in hops, that is, the part that contains the alpha acids, which was first measured in 1888, was the best test of the keeping qualities they would bring to beer. Gradually brewers began to buy hops on their soft resin content, and growers began to plant varieties that contained a higher proportion of soft resins. Researchers at Wye College, near Ashford in Kent cross-bred English hop varieties with native American hops, which generally have twice the alpha acid content of Europeans, but a “fruity” aroma English brewers had looked down upon. One, Bramling Cross, born in 1927 of a female Bramling hop with a wild male hop from Manitoba in Canada, has become appreciated for its “blackcurrant” nose. Others have had the fruitiness bred out, and the high alpha acid kept in. Many hop varieties in use today in Europe, the United States and Australia are based on hops first developed at Wye College.

However higher alpha acid content in the hops means fewer hops are needed in the beer means fewer hops need be grown. Total hop cultivation in England in 1976 was 17,000 acres. By 1997 it was just 7,500 acres, with 2,400 acres in Kent, 2,300 in Herefordshire, 870 in Worcestershire, 300 in Sussex and tiny amounts in Surrey, Hampshire and Oxfordshire. In 2006 that total had dropped to only 2,400, just two per cent of the worldwide acreage.


The flowers of the hop plant have been used in the brewing of beer for centuries. First introduced to the UK from continental Europe in the 16th century by Dutch farmers, hops soon became the most important crop of the Kent area. A trailing plant, the hop plant is trained to grow up strings between poles, and tended to by workers on stilts. The harvesting of hops was highly labor intensive, requiring more workers than the local population could supply. Whole families from the poorer areas of London would migrate to the hop fields of southeast England at harvest time. By 1870, special trains were being run to transport families to the hop fields. Londoners who could not afford to get out into the country normally looked on harvest time as something of a holiday. On arrival, though, conditions were squalid. Families lived in barns, tents, stables, even pigsties. Hygiene was poor and disease spread — in 1849 cholera killed 43 hop pickers on a single farm. In the 1860s, two priests began to visit the hop fields and campaign for improved conditions, eventually forming the Society for Employment and Improved Lodgings for Hop Pickers in 1866. One of the priests had a team of twelve missionaries by 1889. Hop pickers were gradually given improved accommodation in "Hopper Huts,” rudimentary timber or brick shacks. In the 1950s, mechanized harvesting began replacing laborers on hop farms and the tradition declined. The Hopper Huts were demolished or turned into houses, though some were preserved in museums.

But in the 19th Century with the huge increase in acreage went an expansion in the hop picking “phenomenon” – the mass arrival of families from the East End of London, Portsmouth, Birmingham and other towns for their annual hopping “holiday”.An acre of hops could employ 200 pickers at a time. The migration has been variously estimated at 350-450,000 people, a large proportion into Kent and Sussex. In a country with a population of 8 million people this was a prodigious movement of people, for example compared with itinerant foreign farm workers of the 21st Century. Big hop growers took in 3000 or more pickers. In the early 1800s the pickers earned a penny a bushel, rising to 2d later on.
Special trains were laid on from East End Stations. Pickers were housed in very rudimentary huts and sheds around the hop gardens. With so many incomers there were inevitable tensions with the country residents and sometimes drink fuelled violence. Extra Constables were deployed during the season. William Marshall writing in 1798 said that the roads swarmed with strolling pickers “living as much in a state of nature as American Indians or the savages of the Southern Hemisphere” and plundering the countryside. The Oast acted as a social centre during the picking season, especially for the end of season party.

There was a Victorian tendency to take a romantic and sentimental view of the blessings of hop picking in the country, a wonderful break from their benighted life in urban slums and the Docklands. This was an opportunity for clergy, temperance causes and charities to improve the moral and physical welfare of hoppers. Thus, John Marsh in Hops and Hopping, wrote in 1892: “what the banks of the Riviera are to the children of the aristocracy, the banks of the Medway and the Stour are to the children of the poor”. “When father and mother sit by the cold firegrate and empty cupboard and the children cry of hunger, they comfort one another with the words – hopping’s coming”. The author goes on to comment that the effect of philanthropic missions is “very remarkable on the improved character of the hoppers and the elevation of the moral tone of their lives.” Health remained a concern. In 1849 43 hop pickers at East Farleigh who worked for Mr Ellis, the inventer of the press died in a cholera outbreak. A wooden cross in the churchyard was erected “in memory of forty three strangers”. Their names were evidently not thought worth recording. Reports arrived from America in the 1870s of a mechanical hop picking machine, but replacement of the hop pickers by machines did not come until the mid 20th Century. In the 1960s most hop farms still picked by hand. But by the 1980s mechanised picking had almost entirely taken over.

Before the days of mechanised farming, hop picking was a labour-intensive process, requiring a vastly greater number of people than were available locally. Whole families (including children who could have been at school) from London, particularly the south-east and east of London, would leave their homes and spend their time working in the Wealden hop-fields of Kent, Sussex, Surrey and Hampshire. By the 1870s, the South Eastern Railway and the London Chatham and Dover Railway were running Hop Pickers' Specials to transport Londoners to the towns and villages at the start of the season. Similar trains were run to serve the pickers in Herefordshire and Worcestershire. An estimated 250,000 hop pickers from London were travelling to Kent by the early twentieth century[citation needed]. In Hampshire, some workers came from the Portsmouth, Southampton and Salisbury areas. Hopper huts were also provided in Herefordshire and Worcestershire. Workers in these two counties would come from the Black Country or South Wales. The miners from South Wales remained at home and carried on working at their pits. Accommodation in the early Victorian period would be in barns, stables, cattle sheds, pigsties, tents or the roof space of buildings. This led to problems with hygiene and therefore health. An outbreak of cholera killed 43 hop-pickers at East Farleigh in September 1849.

In 1865, the Rev J Y Stratton began a campaign to improve the conditions of the hop-pickers. Also during the 1860s, the Rev J J Kendon, visiting Goudhurst, was appalled at the plight of the hop pickers and began campaigning for improvements. This led to the formation of the Society for Employment and Improved Lodgings for Hop Pickers in 1866. The first bylaws covering hop-pickers' accommodation were adopted at Bromley in Kent under the Sanitary Acts Amendment Act, 1874. Kendon made his headquarters at Curtisden Green and by 1889 had a team of over a dozen missionaries. In 1898, Father Richard Wilson, a priest from Stepney, London, became curious as to what his parishioners did when they disappeared. He persuaded one family to take him with them. He too was appalled by the conditions the pickers had to live in, but would go with them each year, gradually gaining their trust. From 1897 he rented a cottage at Five Oak Green for 2s.6d a week, furnishing it with cots and providing a nurse. Thus, the Little Hoppers Hospital was born. It was very busy that year, as there was an outbreak of smallpox. A few years later, he was able to rent a larger cottage. By 1906 most of the districts of Kent had laws to similar effect, and many farms had hopper huts by 1914. In 1910, Father Wilson bought the Rose and Crown public house in Five Oak Green and turned the building into the Hoppers' Hospital which provided free medical care for hop pickers as well as social activities including singing, dancing and film shows as an alternative to drinking in local pubs. The building bore the legend "E and H Kelsey's Fine Ales, Stout and Porter Sold Here" over three lines, to which Father Wilson simply added the word "not" before the last two words. This Hoppers Hospital was in operation for over 60 years and the historic grade II listed[8] building is still owned by the Stepney-based charity founded at Wilson's church, the Red House and used for holidays by groups from East London.[9][10] The Salvation Army also used to visit the hop pickers in the fields and attend to their welfare. There was also a Hoppers Hospital at Marden, which was not connected with the one at Five Oak Green.

The standard size of a Hopper Hut was either 9 feet (2.74 m) by 9 feet (2.74 m) or 8 feet (2.44 m) by 10 feet (3.05 m), though some were as large as 14 feet (4.27 m) by 14 feet (4.27 m). Early huts were of timber, and during the latter half of the 19th century corrugated iron sheets were used to clad them. Following the abolition of the brick tax in 1850, brick huts were built. Exterior walls were 9 inches (230 mm) thick and partitions between individual huts 4½" (115mm) thick. During the 1930s and 1940s, some Hopper Huts were built of 18 inches (460 mm) by 9 inches (230 mm) breeze blocks, these being cheap and plentiful after the end of the war. A few huts were made from pre-cast concrete at this time. Nissen Huts were also used as accommodation for hop-pickers.

The huts generally had an earth floor, and were lit by either candles or paraffin lamps. Water would be via a standpipe which had to be within 150 yards (140 m) and sanitation provided by a dedicated toilet block, usually with an earth closet. There would generally be a dedicated cookhouse which the hop-pickers would use to prepare their meals. It was generally discouraged by the farmers for the pickers to have fires in their huts. A few brick built huts were provided with custom built fireplaces and chimneys. The interior of the huts was generally limewashed or distempered. The furniture within the huts was provided by the pickers. Only very basic bedding was provided - hay and ferns, faggots and straw, then faggots and a palliasse. Some pickers built themselves basic beds of scrap timber with a palliasse. In the late 1940s and 1950s ex-army steel frame beds were used.

George Orwell tried his hand at hop-picking at Blest's Farm, somewhere near West Malling, in September 1931, travelling down from London disguised as a tramp. He spent his time living in a Hopper Hut made of tin (corrugated iron), thus discovering that fruit and hop picking was not quite the idyllic life described by many scholars and writers of the time. Orwell earned 9/- in a week, and observed that a family of gypsies who had picked every year since birth earned 14/- each. His account was published in A Clergyman's Daughter in 1935. By the late 1950s, hop-picking was becoming an increasingly mechanised process. This, plus the improvements in sanitation at home, led to a decline in the need for Hopper Huts. The vast majority of huts today are no more. A few survive derelict or converted to residential or other use. Hopper Huts can still be seen today at Grange Farm, Tonbridge and Downs Farm, Yalding. A set of Hopper Huts from North Frith Farm, Hadlow, has been re-erected at the Museum of Kent Life, Sandling. These were a row of six huts built of brick under a peg tiled roof, with integral fireplaces.

An oast, oast house or hop kiln is a building designed for kilning (drying) hops as part of the brewing process. They can be found in most hop-growing (and former hop-growing) areas and are often good examples of vernacular architecture. Many redundant oasts have been converted into houses. The names oast and oast house are used interchangeably in Kent and Sussex. In Surrey, Hampshire, Herefordshire and Worcestershire they are called hop kilns.

They consist of a rectangular one or two storey building (the "stowage") and one or more kilns in which the hops were spread out to be dried by hot air rising from a wood or charcoal fire below. The drying floors were thin and perforated to permit the heat to pass through and escape through a cowl in the roof which turned with the wind. The freshly picked hops from the fields were raked in to dry and then raked out to cool before being bagged up and sent to the brewery. The Kentish dialect word kell was sometimes used for kilns ("The oast has three kells") and sometimes to mean the oast itself ("Take this lunchbox to your father, he's working in the kell"). The word oast itself also means "kiln".[1]

The earliest surviving oast house is at Golford, Cranbrook near Tunbridge Wells. It dates from sometime in the 17th century and closely mirrors the first documentary evidence on oasts soon after their introduction of hops into England in the mid 16th century. Early oast houses were simply adapted barns but, by the 18th century, the distinctive tall buildings with conical roofs had been developed to increase the draught. At first these were square but around 1800 roundel kilns were developed in the belief that they were more efficient. Square kilns remained more popular in Herefordshire and Worcestershire and came back into fashion in the south east in the later 19th century. In the 1930s, the cowls were replaced by louvred openings as electric fans and diesel oil ovens were employed.

Hops are today dried industrially and the many oast houses on farms have now been converted into dwellings. One of the best preserved oast house complexes is at the Hop Farm Country Park at Beltring.

The purpose of an oast is to dry hops. This is achieved by the use of a flow of heated air through the kiln, rather than a firing process.

Hops were picked in the hop gardens by gangs of pickers, who worked on a piece work basis and earned a fixed rate per bushel. The green hops were put into large hessian sacks called pokes. These would be taken to the oast and brought into the stowage at first floor level. Some oasts had a man-powered hoist for this purpose, consisting of a pulley of some 5 feet (1.52 m) diameter on an axle to which a rope or chain was attached.The green hops when freshly picked had a moisture content of some 80%; this needed to be reduced to 6%, although the moisture content would subsequently rise to 10% during storage.

The green hops were spread out in the kilns. The floors were generally of 1 1⁄4-inch (32 mm) square battens nailed at right angles across the joists, placed so that there was a similar gap between each batten, and covered with a horsehair cloth. The hops would be spread some 12 inches (300 mm) deep, the kiln doors closed and the furnace lit. When the hops were judged to be dried, the furnace would be extinguished and the hops removed from the kiln using a scuppet, which was a large wooden framed shovel with a hessian base. The hops would be spread out on the stowage floor to cool, and would then be pressed into large jute sacks called pockets with a hop press. Each pocket contained the produce of about 150 imperial bushels (5,500 l) of green hops. It weighed a hundredweight and a quarter (140 pounds (64 kg)) and was marked with the grower's details, this being required under The Hop (Prevention of Fraud) Act, 1866.

The pockets were then sent to market, where the brewers would buy them and use the dried hops in the beer making process to add flavour and act as a preservative. Oasts sometimes caught fire, the damage sometimes being confined to the kilns (Castle Farm, Hadlow), or sometimes leading to the complete destruction of the oast (Stilstead Farm, East Peckham in September 1983 and Parsonage Farm, Bekesbourne in August 1996).

The earliest description of an oast dates from 1574. It was a small building of 18 feet (5.49 m) by 9 feet (2.74 m) in plan, with walls 9 feet (2.74 m) high. The central furnace was some 6 feet (1.83 m) long, 2 feet 6 inches (760 mm) high and 13 inches (330 mm) internal width. The upper floor was the drying floor, and only some 5 feet (1.52 m) above the ground floor, hops being laid directly on the slatted floor rather than being laid on hessian cloth as was the later practice.

In many cases, early oasts were adapted from barns or cottages. A chapel at Frindsbury is also known to have been converted to an oast,[6]as was one at Horton, near Canterbury.This was done by building a kiln within the building, dividing it into three, the upper floor being used to receive the "green" hops, dry them and press the dried hops. Examples of this type of conversion can be seen at Catt's place, Paddock Wood and Great Dixter, Northiam.Later conversions of barns and cottages would be by either building an integral kiln within one end of the building, as seen at Biddenden, Kent, or adding kilns externally to the existing building, as seen at Barnhill Farm, Hunton, and also at Sutton Valence.

An agreement for the building of an oast in Flimwell in East Sussex in 1667 gave the size of the building as 30 by 15 feet (9.1 by 4.6 m) and another to be built there was to be built in 1671 being 32 by 16 feet (9.8 by 4.9 m) or 17 feet (5.2 m), having two kilns. The earliest surviving purpose built oast is at Golford, Cranbrook, built in 1750. This small timber framed oast is 21 by 15 feet (6.4 by 4.6 m) in plan, and has a hipped tiled roof. It has one kiln, and a single cowl in the ridge of the roof.

In the early 19th century, the traditional oast as we now know it started to be built. A two or three storey stowage, with between one and eight circular kilns. Kiln sizes generally ranged from 12 feet (3.66 m) to 18 feet (5.49 m) diameter, with a conical roof. Towards the end of the 19th century square kilns were constructed. These generally ranged in size from 16 feet (4.88 m) to 20 feet (6.10 m) square. An oast at Hawkhurst was built with two octagonal kilns, 15 feet (4.57 m) across the flats.

In the 20th century, oasts reverted to the original form with internal kilns and cowls in the ridge of the roof (Bell 5, Beltring). These oasts were much larger and constructed of modern materials. Oasts were built as late as 1948 (Upper Fowle Hall, Paddock Wood) or 1950 (Hook Green, Lamberhurst).

Very modern oasts bear little resemblance to traditional oasts. These vast buildings can process hops from several farms, as at Norton near Teynham in Kent, built in 1982. Oasts were built of various materials, including bricks, timber, ragstone, sandstone. Cladding could be timber weatherboards, corrugated iron or asbestos sheet.Many oasts were timber framed buildings, although some were built entirely in brick, or ragstone if this was available locally. Some oasts were entirely brick except the front and floors, which were timber. Internal kilns were built of timber or bricks. External kilns were built from bricks, ragstone and bricks, or sandstone. A rare material usage was at Tilden Farm, Headcorn where the kiln was built from Bethersden Marble. During the Second World War, a few kilns were built with a basic timber framing and clad in corrugated iron (Crittenden Farm, Matfield).

Kiln roofs, where the kiln was external, were generally built of a timber frame and covered in either peg tiles or slate. Some oasts had conical kiln roofs built of brick, these were covered in tar or pitch to keep them weatherproof. A few oasts had square kilns with brick roofs, again covered in tar or pitch. The top of the roof was open, and carried a cowl or louvred vent. Oasts are generally associated with Kent, and the oasthouse is a symbol associated with the county. They are also found in Sussex, Surrey and Hampshire.

Oast houses are often called hop kilns in Australia. Tasmania is a major hop-growing area, as were parts of Victoria. During the 19th century, some of the Kentish hop growers emigrated, and took hops with them. Initially, Tasmanian oasts were converted from existing buildings (New Norfolk, Ranelagh) but later purpose built oasts were built (Valley Field, Bushy Park). These oasts had louvred ventilators instead of a cowl. The New Norfolk oast was converted from a watermill and is now a museum. Another location that has oasts was Tyenna. A modern oast of 400 by 200 feet (120 by 60 m) was built at Bushy Park in 1982.

With the increasing mechanisation of the hop-picking process, many oasts fell into disuse. Some were demolished, others became derelict. Increasing demand for housing has led to many oasts being converted into houses. Local councils nowadays are generally much stricter on the aesthetics of the conversions than was the case before planning law came into being. Often kiln roofs have to be rebuilt, and cowls provided on converted oasts.

The earliest example of an oast being converted to a house is Millar's Farm oast, Meopham, which was house-converted in 1903 by Sir Philip Waterlow.Other conversions of oasts for non-residential purposes include a theatre (Oast Theatre, Tonbridge, Oast house Theatre Rainham, a Youth Hostel (Capstone Farm, Rochester, another at Lady Margaret Manor, Doddington – now a residential centre for people with learning difficulties), a school (Sturry), a visitor centre (Bough Beech reservoir) offices (Tatlingbury Farm, Five Oak Green and a museum (Kent Museum of Rural Life, Sandling, Preston Street, Faversham, Wye College, Wye and the former Whitbread Hop Farm at Beltring. The National Trust owns an oast at Outridge, near Brasted Chart which has very rare octagonal cowls, one at (Castle Farm, Sissinghurst), converted to tea rooms and another at Batemans, Burwash which has been converted to a shop, with the cowl being replaced by a dovecot.