Dalham Malt Kiln

The processes of Malting through the Ages

Origins and short history of Malting as an industry

Malt is artificially germinated grain, usually barley, with germination arrested at the critical point by kilning. It is a prime ingredient in the production of beer and whisky.

In England the main use of malt was for brewing beer. Beer has been made on a domestic scale throughout history and on a local level in taverns from medieval times onwards but in the 18th century the development towards large-scale industrial breweries started and was to continue throughout the next two centuries. In consequence, there were not only many maltings of various sizes, but they were wide spread across the town and country.

There are references to malt being produced in England since the eleventh century, but early production was possibly in barns and the kilning may have been done in domestic ovens. However, for at least the last 500 years it has also been made in purpose built malthouses with kilns specially designed to cure the green malt. 


These buildings are known as floor maltings because the germinating barley was spread out to grow on a floor.

Prior to the 18th century both the malting industry and the brewing industry were generally small scale. But while the brewing industry was small scale it was also often domestic. In the mid-18th century some sixty per cent of beer production was private, and much of the rest was brewed by retail brewers operating from inns

In contrast, in the malting industry, although the production of malt may have been small scale it was not domestic in the same way as the brewing industry. It was in the hands of specialist maltsters who were a feature of almost every market town. Thus while a household might produce its own beer, it was less likely to produce its own malt, unless on a farm.


The Processes involved in Producing Malt

Barley Storage, Drying and Cleaning

The barley has to be cleaned and stored prior to use to ensure its dormancy is broken. In the pre-industrial period when most maltings were small scale operations, the barley was either stored in ricks and a granary on the farm until shortly before it was used. The threshing and winnowing would remove most of the small stones and the chaff, but there was probably additional dressing at the malthouse, and simple cleaning equipment can be found in early malthouses.

Later, when the barley came from the farm directly after harvesting there were more substantial grain cleaning or dressing machines as well as specific machines for removing half corns, all driven by some form of power. Although, barley on the straw could safely be stored in a rick, when it was stored in the malthouse, it was often necessary to reduce the moisture content in the barley to about 12 per cent so that it could be stored safely. Special barley kilns were built from about the mid 19th century.


The first stage in the malting process, after drying and cleaning is the steeping of the barley in the cistern to begin germination. From at least the end of the 17th century the most usual type of steeping cistern, until the last quarter of the 19th century, was a rectangular trough constructed of stone or brick and made water tight with either lead or later, cement or tiles.

Once the barley had been steeped it had to be removed from the cistern. In the rectangular flat bottomed steeps, the usual method of emptying was by shovelling the wet grain out and into the couch frame or onto the growing floor.


The next stage in the malting process was couching whereby the steeped grain was rested for a period, in a heap of sufficient depth, so that it could gain a little heat.

Once couching was complete, the maltsters shovelled the barley out onto the germinating floors.


From the couch or the steep the soaked barley was spread out onto the floor to grow on a germinating floor. These long open floors usually with restricted head-room and often supported by ranks of wooden or cast iron columns give maltings their characteristic external massing and distinctive internal appearance. The best growing floors were covered with a screed surface, or quarry tiles laid on the diagonal, but other materials used included slate, asphalt, brick pammets, or tamped chalk. Wood was generally avoided in this damp environment and features such as skirting boards were often of slate or corners were finished with tiles.

To maintain an even temperature in a malthouse ventilation was provided, traditionally by windows and louvres in the long elevations of the building.

The growing batch of wetted barley is referred to as a “piece”. As germination progressed the rootlets began to grow and it was necessary to turn the growing grain to prevent it from matting together and to ensure the growth was even.

When growing was finished, the green malt has to be moved either into a heap for withering or straight onto the kiln. Transferring the green malt to the kiln was hard work but, until the advent of wide spread mechanisation, was often done by men with shovels. In consequence where the malthouse had more than one growing floor, the kiln drying floor was often below the top germination floor. This made shovelling the wet grain from the top floor onto the kiln easier


At the end of the growing period it was not uncommon to wither or dry off the green malt before putting it onto the kiln for curing. Thus the green malt was heaped up and allowed to lie for twelve hours. It was considered good practise to wither, although with improved kilns being increasingly used from the late 19th century onwards, its practise became less essential


When the green malt, as partially germinated barley is called, has reached the required extent of growth, it is ready to go to the kiln. The kilning of the malt arrested germination and therefore halted the breakdown of the starch molecules. It reduce the moisture content, to about three per cent which is necessary for safe storage and produces an ideal grain for grinding to grist in the brewing process. Kilning also gave colour and flavour to the malt.

It is very likely that in the early years malt was kilned in domestic bread ovens, and there are references which refer to drying malt in the sun! Purpose-built malt kilns were in existence by at least the thirteenth century. At that date the malt was dried on hair cloths. It would seem that later on some kilns had their hair-cloths laid on perforated stone tiles, although it was more common for the hair cloths to be laid on what are referred to as wooden rafters. It was still common to lay the malt on a hair-cloth in the 18th century, but as early as the 1730s other materials were being used and they included iron plate frames and tile frames, both of which had holes in them, and brass wired frames and iron wired frames. The remains of perforated ceramic tiles are sometimes found in the vicinity of old maltings from the 18th century onwards. By the mid-19th century the perforated tiles were of a standard size, a foot square (30cm square). A few firms became well-known for their manufacture. Woven wire floors remained in use but few now survive and by the last quarter of the 19th century wedge wire kiln drying floors were becoming more commonly used.

The green malt is laid on the drying floor to a depth of about eight to twelve inches (20 to 30cm), although in the 18th and 19th centuries the depth might be as little as 4 inches (10cm). The length of time it took to kiln the malt has varied over the centuries. In the 16th and 17th centuries the literature is not specific, simply stating that the malt is kilned until it is done and a check is made by hand. By the 18th century it would seem that kilning lasted sometimes as little as four hours. and sometimes as much as twenty hours, although the length of kilning seems to have depended in part upon the construction of the kiln and the type of fuel being used. During the 19th century the kilning time increased and was generally three or four days. On some modern kilns, the curing time has been reduced to just twenty four hours.

The type of fuel use also depended upon what type of malt was being produced. Well-dried billets were used for the kilning of brown malt. It was always considered that coke was the best, especially for making pale and amber malts. By the 19th century the usual fuel was anthracite or coke and as the combustion products usually passed directly through the malt a fuel of low arsenic content was essential. By the later 20th century gas or oil are used, with gas usually preferred to oil while anthracite is still used in Suxé anthracite hopper furnaces.

When kilning was completed, the malt was removed promptly from the kiln. Traditionally by men shovelling the malt off. Later there were more mechanical means, either by dropping it through the floor into chutes, or, more recently, by the floors tipping up and the malt dropping into hoppers and chutes.

Kilns, where they survive, are the most distinctive external features of a malthouse. Early maltings might have round, cone shaped roofs. Generally surviving kiln roofs are pyramidal in shape, although sometimes they had a rectangular-shaped hipped roof with cowls protruding from the ridge, or a long ridge vent cowl.

Malt Storage and Cleaning

Finally, the kilned malt was dressed (the rootlets removed and the grain cleaned) and then stored until it was required for brewing usually for at least a month before it was used. Unlike barley storage, it was usual for the malt to be stored at the maltings, sometimes in a block beyond the maltkiln, or on a floor adjacent to the kiln in the main body of the building. To reduce the likelihood of malt gaining moisture it was stored in wooden bins where the wood would absorb any excess moisture though in some prestigious late 19th century maltings zinc lined bins were installed.

Workers Housing

One feature outside the malthouse which is sometimes to be found on site or nearby, is housing for the head maltster and the main workers, as indicated by the name “malthouse cottages” .

The précis above has been taken from the St Edmundsbury Malting web page. The full article can be read here;- http://www.stedmundsburychronicle.co.uk/maltsters/maltingprocess.htm

More information about the Malting Kiln can be found on the Dalham Village website at www.dalham.com.