Leah’s Beer School: Lesson 45

What is Malt? 

Beer is comprised of four essential ingredients: water, malt, hops and yeast. While newly developed yeast strains and novel hop varieties are constantly at the forefront of beer news, the role of malt in beer is often understated. In reality, malt is the backbone, or essential support system, of beer.

Malt can be derived from a variety of grains, but barley is the most frequently used grain in beer. Malt-based wort offers both sugars and nutrients that yeast requires for fermentation, hop bitterness relies on malt sweetness as a counterpoint to achieve balance. Starches contained in barley are converted into sugars, through which ferment into alcohol. The protein in barley assists with foam production, head retention and stability.

Malting involves soaking grains in water, which activates germination and is finished when a small sprout has grown. During germination, a grain’s starches are converted to fermentable sugars, its cell walls and proteins start to break down, readying it for brewing. The grain is now referred to as green malt, and germination can be stopped. Kilning uses a combination of heat and air to halt germination, and once the grain is dried, it is called malt.

History of Malting 

Historical artifacts reveal that beer production among Egyptian civilizations had not only begun by 4000 BC, but it had by then evolved into a disciplined technology. Some evidence suggests that early Egyptians produced malt by placing it in a wicker basket and steeping it in an open water well. To germinate the grain, the basket was raised about water level. The rate of germination was controlled by adjusting the position of the basket within the well. As heat developed and germination progressed, the basket was lowered to cool the grain and inhibit growth. Drying likely involved spreading grains on the ground to dry naturally in the sun.

Malting progressed from baskets and open wells, to cisterns and caves, to malt houses built adjacent to a water source. By the late 19th century, developments in malting machinery, drastically increasing the capacity for malt production. 

Types of Malt 

The two main factors involved with producing different types of malt are the duration and temperature of kilning and roasting. Base malts are the primary, nearly exclusive source of sugars in beer, they provide the foundation for beer. The base malts are often described as being the workhorse of the grain bill.

Specialty malts, undergo the same malting process as base malts, but have received additional treatments, like roasting, to gain different colours and flavours. Malts roasted for longer and at a higher temperature, will produce darker, richer malts, but extended kilning also reduces the availability of fermentable sugars. As a result, darker malts generally account for a relatively small amount of a beer’s grain bill, where the bulk of it is comprised of base malts. 

Often described by brewers as the soul of beer, malt has a rich set of characteristics that provides the basis for so many different flavour expressions.  Malt plays a significant role in determining the flavour, mouthfeel, colour and aroma of a beer.

(Leah is a Toronto based freelance writer as well as Head Beer Weenie and a server at C’est What)