Only a few Scottish distilleries still malt their barley themselves, many malting floors have long been mothballed. All the more exciting, what actually happens there on the remaining malt floors and how the barley is prepared for firing.
Why is barley malted before whisky distillation?
Before malt whisky is made, the barley is almost always malted. This is because the barley contains the required sugars in an unprocessed starch form. For this sugar to be useable for fermentation it must first be converted into a simple maltose sugar that the yeast can then convert into alcohol. Happily barley also contains within the enzymes required to convert this starch and these are released during the malting process. Although not all whisky is made using malted barley, other oats such as rye, wheat and even unmalted barley may be used some malted barley is almost always added into the mashbill, this is because of the high diastatic power](/fundamentals/diastatic-power/)(amount of enzymes) within malted barley which allows it to convert sugar in other grains as well. In the US and Canada commercial enzymes may be used in place or malted barley in order to make 100% rye or corn whiskies.
What is a malt floor?
A typical malting floor can be thought of as a large attic or garage: It is a large room, usually with supporting columns instead of walls, on which the barley is spread out on the threshing floor (the paved floor). In principle, you don’t need more. There are very different rooms that are used as malt floors in Scotland and many don’t even look that romantic. It is important that there is a suitable climate on the malting floor, which is not too warm or cold and whose temperature fluctuates only slightly. These influences have a direct impact on the quality of germination and barley. Adequate ventilation is also required for malting, otherwise the barley will germinate poorly.
How does malting grain work?
When grains are malted, the grains are germinated in a targeted manner. Only the first three barley quality levels (out of a total of nine) are used. For malting, the cleaned and dry cereal grains must first be moistened evenly. The grain is then spread out on the malting floor, whereupon it ideally begins to germinate within approximately four to seven days.
During germination, the barley has to be turned manually (or mechanically nowadays) several times a day in order to achieve an even microclimate in the grain. If the barley were not turned, irregular germination would result. In the past, barley was only turned by hand and led to physical impairments of the workers over the years (the so-called “monkey shoulder” was a well-known affliction).
As already briefly outlined above, the germination produces enzymes and part of the starch is converted into sugar (maltose) and thus available for fermentation to alcohol.
So that the germinating grain does not become a fully grown plant, the desired ingredients are preserved and the malted barley becomes storable, the germination must be interrupted. For this, the barley is dried (“kilned”) and the moisture necessary for germination is removed.
Traditionally, this is done over a fire. The numerous pagoda roofs at Scottish distilleries point to the Kiln and are reminiscent of this custom. On Islay in particular, peat is burned during the barley drying process, which is responsible for the characteristic taste of these whiskies.
Why do only a few distilleries malt themselves?
As you can imagine, malting the barley for the Scottish distilleries requires a great deal of work and involves numerous imponderables. The primary obstacle is capacity, distilleries are often producing far more whisky than the original sites were ever built to. Huge malt stores would have to be kept and operated for the quantities to be produced in order to ensure a constant supply, with the increased space and staffing requirements. Cost and quality are also large considerations. The quality of the malted barley can fluctuate depending on the prevailing climate conditions. Floor malted barley often have lower spirit yield compared to commercial maltsters, a difference of 5-8 litres per ton is a significant cost factor.
While many experimented in the past with Saladin boxes most distilleries now buy the malted barley from specialized maltings. The massive Port Ellen Maltings on Islay is actually incredibly small by industrial standards. Industrial malting plants use modern technology to produce the barley efficiently, in high quality and with the desired specifications (phenol values for peated whiskies) in large centrifuges.
And so only a few Scottish distilleries malt their barley on their own malting floors. They continue the tradition, but often also keep an eye on the visitors who like to take a look at the malt floors during a distillery tour. Most malting Scottish distilleries produce only a small part of the malted barley they need - the rest are also supplied by large malting plants.
Scottish whisky distilleries with floor maltings
- Highland Park
In addition to these distilleries Thamdu also operates a Saladin box, and the Roseisle and Glen Ord distilleries have their own maltings as well. The remainer rely upon industrial maltings.
Ardnamurchan distillery isn’t on the way to anywhere of interest and so one only hardcore whisky fans are likely to visit. Located in Glenbeg on the Ardnamurchan peninsula in the Highlands, Ardnamurchan is Scotland’s westernmost whisky distillery. The distillery is a fairly recent addition, the independent bottler Adelphi received planning permission for what is now the Ardnamurchan distillery back in 2012. The first new make was laid down in 2014.
With eleven stills, Balvenie is one of the larger Speyside distilleries. Nevertheless, you still malt part of the barley yourself. Up to 15% of the barley required is produced on our own malting floors, which can also be viewed as part of a tour.
BenRiach’s malting floor, to a certain extent, prevented the distillery from disappearing from the whisky map: in 1900 the distillery had been in operation for two years when it had to close again. Only the malt floor remained in operation and supplied malted barley for Longmorn. After troubled times, barley has been malted again and again for the BenRiach whiskies since 2012. The exact proportion of self-malted barley in the production is not known.
Bowmore was founded in 1779 and is one of the oldest distilleries in Scotland. You also feel connected to this tradition when malting. According to the distillery, up to 50% of the malted barley can be produced on its own malting floors.
Laphroaig also continues to operate a malting floor, with approx. 15 to 20% of the malted barley being produced in-house. The barley is dried over burning peat bales in its own oven - here lies the secret of the strongly smoky and medicinal Laphroaig taste.
The Highland Park single malts are distilled from a mixture of peat and undistorted barley: the peat for drying comes from the nearby Hobbister Moor and is said to contribute to the special taste of the Highland Park whiskies. Since you do not want to endanger this special characteristic, up to 20% of the malted barley is prepared in its own malt floors and then kilned over the burning peat. The other 80% are supplied by the mainland.
The small Kilchoman distillery on Islay malted part of its barley itself. According to their own statements, around 20% of the malted barley comes from their own malt floor, which is housed in a corrugated iron warehouse and can be viewed on tours.
Springbank is the only Scottish distillery that works completely independently from malting to bottling: on Springbank’s Malting Floors, an impressive 100% of the barley required is malted itself. The Campbeltown distillery is one of the few remaining whisky manufacturers worldwide that malted completely itself.