What is malt, how’s it made and its role in the brewing process.
Malt is a general term for a grain (usually barley), that has been steeped to start germination, and then exposed to heat to halt the germination process and reduce moisture, known as kilning.
This helps the grain convert some of its starches into sugars, which is then accessible to the yeast to be fermented into alcohol.
Malt is one of the 4 main ingredients that goes into the brew, alongside water, hops, and yeast. Malt and hops are used in varying proportions, resulting in different levels of sweetness, crispness and bitterness, as well as other flavours unique to the different varieties hops. Other adjuncts may be used for many reasons, including the use of fruit for its flavours, or rice added to the grain bill to help contribute to a lighter colour without much impact on the flavour.
Within the kilning process, you can produce different types of malt depending on how much heat is applied and for how long. The higher the temperature and the longer the heating process, the more of a bitter/charred, coffee like flavour gets imparted into the beer, so brewers typically only use these types of malt sparingly. Lighter malts are generally used as a base, while the “specialty malts” are used in limited quantities for their flavour and colour.
The colour of malt is measured in Lovibond, which can also be used to somewhat assume the flavour profile. As an example, “Lager malt” is generally around 1.6-2L (Lovibond), while “Chocolate malt” is measured around 350-400L. In summary, the higher the number, the darker and more roasted the malt in both taste and appearance.
Brewing beer can be done with either malt grains or malt extracts. Malt extract comes in either liquid or dehydrated form, all types having their differences, giving brewers multiple choices and preference. There doesn’t seem to be a right or wrong answer to whether you should brew with grain, LME or DME, as each can produce great beer if you follow the process correctly.
Liquid Malt Extract (LME) is made by lowering the water content of wort (pre-fermented beer) until it becomes a syrupy consistency. Dry Malt Extract (DME) is made by passing LME through an atomising nozzle, resulting in a fine powder.