All beer is based on germinated, dried cereal grains, better known as malt. A large number of cereal varieties can be malted, but barley and wheat are particularly suitable for the purpose because they have a naturally high starch content. The cereal’s starch is the platform for the formation of the sugar that eventually turns to alcohol. The cereal cannot be used for brewing before it has been malted (germinated) because it does not naturally contain the enzymes capable of converting the starch to sugar. These enzymes are only formed during the malting process, in which the cereal kernels have to be broken down so that the cereal becomes easier to grind and therefore the starch grains become more accessible.
In the production of malt, the cereal kernels are softened in water, which causes the cereal to germinate. The germination process is interrupted by drying before the kernels sprout at the top, or more precisely when the acrospire has reached 2/3 to 3/4 of the kernel’s length. The roasting temperature, water content and interruption point determine the type of malt.
Roasting has a particular influence on the beer’s colour and taste. As with coffee beans, the malt becomes darker and stronger in taste the higher the temperature at which it is roasted. Malt can thus be broken down into three different categories. Firstly, pale basic malts, which are lightly roasted, air- or wind-dried and typically extra rich in enzymes. Secondly, kiln-dried malts, which are more thoroughly roasted than basic malts, vary in colour from brown to black and are sometimes bitter with notes of chocolate. Thirdly, caramel malts, which are heated while wet before roasting, promoting sweetness in particular.
Pale malts typically account for the majority of the malt in a beer, while kiln-dried and caramel malts (sometimes known by the generic term ‘special malts’) are used to supplement colour and taste. For example, a weissbier (wheat beer) is brewed solely with pale malt, while a stout contains lots of kiln-dried malt. The basic malts, however, are essential to the beer because they provide the primary source of starch. Typically, you use 50–75% basic malt for a beer. The remaining percentage may comprise a range of combinations of special malts, other cereals, rice, corn, sugar, etc.
The proteins in beer also come from the malt. The protein content has a major impact on the beer’s appearance because it is the protein that produces the head and – in combination with the yeast – can form a more cloudy consistency. Beer types such as witbier and weissbier, for example, are brewed with large amounts of wheat malt, which has a particularly high protein content. It is this that gives these beers their characteristic cloudy look and rich head.
When you buy malt, its colour is defined by an EBC (European Brewing Convention) unit of measurement. The higher the number, the darker the beer colour. You will also come across EBC units in beer recipes, and some breweries include them on their beer labels.
