What is malt?

Malt is shorthand for barley that has undergone a process called malting. Malted barley is the main cereal used in brewing beer and the only one that falls within the German purity laws – the Rheinsheitgebot – under which most of the famous beer producing country’s beer is made, and to which brewers in some other parts of Europe, such as the Czech Republic, also adhere to.

In other places, other cereals are used, such as maize or rice, principally as a way of keeping costs down. Wheat is sometimes used to give the distinctive sharp fruitiness of associated with a wheat beer.

In some parts of the world, the types of cereal used is influenced simply by what is available in local markets. Sorghum is frequently used in beers in parts of Africa for that reason. But malted barley remains the most favoured cereal throughout much of the brewing world because it gives better, if not always cheaper, results.

What does malt give to beer?

The principal role of malted barley is as a source of sugars that provide the potential alcohol content of the beer achieved through the fermentation process. But the type of malt used can also affect the appearance and flavour of the final product.

A pale malt tends to produces a relatively lighter beer in flavour and colour, while a heavily-kilned malt will produce darker, richer flavoured beers, though of course there are many other aspects of the brewer’s art that will affect this.

So what is malting exactly?

Barley is a grain crop that becomes malted barley (or malt) through a process known as malting in a place known with some originality as a maltings. This was often historically often done by larger brewers in their own maltings, and many older breweries still have old maltings buildings which have often been turned into storage, or given over to some other use. But these days it’s more cost effective for brewers to buy malt from specialist companies known as maltsters.

The aim of the malting process is convert the natural starches found in the barley into the sugars that can be used in the brewing process. This is done through a threestage process. First, the barley is soaked in water for around two days, a process known as steeping, which induces the start of the second stage – germination. After steeping, the water is drained from the barley and the grain is stored on a malting floor, in temperature and humidity controlled rooms for three to four days. At this point, protein inside the barley is broken down by enzymes which work on the starch in the malt to convert it into usable sugars.

The final part of the malting process is kilning, in which the germination process is arrested by heating in large kilns. If the germination isn’t stopped, the individual grains of barely would soon spout new shoots and roots. It’s the kilning process that gives different types of malt, by varying the temperature and length of time the barley spends in the kiln.

What different types of malt can we end up with?

Lager malt is the basic type of malt used in most lagers, as the name suggests. In its raw state it has a light yellow-brown colour and a biscuity flavour. Many ales use pale malt as their starting point, but, depending on the recipe of the beer being made, other types of malt may or may not be added to the first, mashing stage of the brewing process. Crystal malt which is slightly darker and has a sweeter toffee-ish flavour, achieved by a longer kilning process. Many ales tend to have a crystal malt presence in them.

Chocolate malt is much darker, blackbrown and has an acrid, burnt flavour.

Dark beers, including heavier ales and stouts, have a high malt content to give them their colour and richer flavours. But the character of the beer will also be influenced by the variety of raw barley that is malted in the first place, just as for hops, or with grapes in wine production. As well as a combination of different styles of malt – pale, crystal or chocolate – a brewer may use a combination of different varieties of pale malt, for example, to achieve a particular character for his beer. These are just a few of the malt types on a wide spectrum, and there are also malt types associated with geographic centres of brewing, such as Vienna malt, used in the amber lager style associated with the city, and Munich malt for dark lagers.

What happens when we’ve got our malt?

Once the malting process has been complete, the malted barley has to be ground into a fine powder, known as grist, to make the centre of the malt grain more accessible and therefore more efficient to make beer from. The ground malt goes into the first stage of the brewing regime, mashing. This involves mixing the ground malt in water heated to around 70ºC, to create a sugar solution, a form that allows the simple sugars to be turned into alcohol and carbon dioxide at the later stage of fermentation.

Mashing also turns proteins from the malt into amino acids which provide nutrients for the yeast, making fermentation more efficient. Some proteins are also turned into polypeptides that provide a generous foaming to the beer.

Once mashing is complete, the spent grain is removed from the liquid that remains, the wort, which then goes off to have the hops added in the next part, the boiling process.

The malt’s job is done, but the fruits of its contribution resonate through the later stages of brewing.

Article is from Issue 3 of Beers of the World magazine