The term whisky refers to any alcohol obtained by distillation of cereals - mainly barley - whether malted or not, in a process of fermentation through tanks and filters, distillation in stills, before it ages in oak casks. The aromas and texture of the whisky come from its ingredients ; this is why malt, its origins and its specifications, are crucial in the quality of the distillation.

Malt whisky

Historically, the term "whisky" referred to products from Scotland (Scotch), Japan, and Canada; with the variant "whiskey" used for Irish and American products.

There are two main categories of 100% barley malt whisky:

  • "Single malt" whiskies, which are made in a single distillery
  • "Blended malt" or "pure malt" whiskies, which are blends that come from several distilleries

"Single grain" whisky, meanwhile, uses 10 to 20% of barley malt as well as unmalted grain.

The type of barley malt used depends on the type of whiskey desired.


The role of malt in whisky production

Malt contains the enzymes necessary to break down complex carbohydrates (the grain's starch), which will be converted into fermentable sugars during the mashing phase. These simple sugars, which will dissolve in the mash during this process will then ferment thanks to the introduction of specific yeast strains.

After fermentation, the liquid (called the “wash” at this stage) is distilled in one or more stills resulting in the “heart” (or spirit). This distillate is then aged in oak casks for several years; at least three years in Scotland.

The degree of alcohol is adjusted depending on the type of whisky desired.

Whisky production

Malteurop and malt distilling

At Malteurop, we produce two main types of malt for the production of whisky:

  • "Pot still" malt, which is by essence the malt used in "single" and "pure malt" whiskies. It is made with specific varieties of barley, selected for their capacity to generate a high volume of alcohol. This fundamental characteristic is expressed in "liters of pure alcohol equivalent" obtained per ton of malt. One metric ton of "pot still" malt will produce +/-1,000 L of whisky at 40°.
  • "High Diastatic Power" (HDP) malt, meanwhile, is reserved for making “grain whiskies” and in particular bourbon in the USA. It provides more enzymes than "pot still" malt, giving it the capacity to break down the starch in unmalted grain, which is used in proportions of up to 80% in this type of whiskey. 5 to 10% of HDP malt is used in the grain mix (corn, wheat, rye, barley).


Whisky glasses