Malt See "Malted Barley".
Malt Bins The Malt Bins are used to store the malted barley until it is required to be processed through the Dresser to remove the roots and shoots and the Roller Mill to produce the malt grist.
Malt Grist Milled malted barley, sometimes just known as grist.
Malt Grist Hopper The Malt Grist Hopper is used to store freshly-milled malt grist until required for mashing with hot water in the Mash Tun.
Malt House The Malt House is the building in which the natural barley goes through the processes to end up as green malt.
Malt Whisky Whisky made purely from malted barley fermented with yeast and distilled in a pot still.
Malted Barley Sometimes known as just malt, malted barley is the grains of barley, softened in water in the Steep, allowed to germinate on the Floor Maltings and dried in the Kiln to stop the germination process. If the Kiln is laced with peat then a peaty aroma is imparted to the malted barley. The malting process converts the stored starch into soluble compounds such as the sugar maltose and by doing so makes fermentation possible.
Malting Controlled germination and drying of grain.
Maltings Buildings used for the production of malted barley.
Maltose Crystalline sugar, chemical formula C12H22O11 , formed by the action of the enzyme complex diastase on starch.
Marrying Process in which blended whisky is left in large containers for a few months after blending but before bottling. Now rarely done.
Mash The mixture of hot water and milled malted barley (grist) in the Mash Tun.
Mash Bill (US term) The proportion of different grains used for mashing.
Mash House The building containing the Mash Tun where the mixture of hot water and milled malted barley (grist) is left to mash and produce the sweet liquid called the wort.
Mash Tub (US term) See "Mash Tun".
Mash Tun The Mash Tun or mash tub is the vessel in which the mixture of hot water and milled malted barley (grist) is left to mash and produce the sweet liquid called the wort. The wort is then passed to the Wort Cooler and Washback.
Mashing The soaking of grist with hot water to extract fermentable starch. In Scotland, three soaks are usually used, at increasingly higher temperatures, to extract almost all of the starch. In Scotland, the third of these soaks is re-used as the first soak for the next batch of grist.
Maturation The time the whisky spends in the cask. During this time, which by law must be at least 3 years - but is usually between 8 years and 25 years, the whisky changes from the clear fiery raw spirit into a mellow malt whisky of a colour varying from the palest yellow to the deepest amber. This mellowing and colour change is as a result of many factors, amongst which are what the barrel was used for previously, the air in the Bonded Warehouse used for maturation, the peatiness of the original water used, the amount of peat used during the malting process, and other known and unknown influences. Once the whisky leaves the cask for the last time, it ceases to age.
Meal See "Grist".
Middle Cut Also known as the heart of the distillation. The second cut of the output from the Low Wines or Spirit Still containing mainly pure alcohol. This is the "raison d'être" of the distillation process.This is the raw spirit that is diverted to the Spirit Receiver and eventually into casks for maturation into single malt scotch whisky.
Mill See "Roller Mill".
Milton Ball A refinement incorporated in pot stills to aid the distillation process by allowing refluxing to take place. Seen as a bulge towards the base of the upstanding column.
Mingling (US term) The process in which straight whiskeys from a number of barrels are mixed together in order to achieve a consistent style of straight whiskey.
Modification A name given to that part of the germination process where the barley sweetens as the starch is converted into sugar.
Morton Refrigerator A particular type of Wort Cooler dating from the nineteenth century and still in use at some distilleries such as Edradour.
Mothballed Distillery A distillery which is temporarily closed, usually in order to prevent the build-up of too much whisky in stock given the trading conditions at the time. Mothballing usually implies some action has been taken to prevent the deterioration of all the buildings, equipment and plant at the distillery. Although such a distillery may not be producing, it could still be maturing stocks in bond.