A gift of nature
The first process of malting is very similar to what occurs in nature when grain is sown in the soil, while malting barley has been malted for over 7000 years.
Malt is used predominantly as the basic raw material for beer and whisky. Malt can also be used to produce other wholesome, nutritious food products. All co-products of the malting process are widely used in the animal feed industry.
How is malt made?
Malting is about controlled germination of barley grains. It is a natural, biological process that is undertaken using controlled conditions (temperature, humidity and air). The aim of malting is to begin the conversion of starch into glucose, which can then be fermented into alcohol in the brewing process.
Malt is made from malting grade cereals, usually barley or wheat, although occasionally other cereals such as rye or oats may be used. The grain is steeped in water, and then allowed to germinate under carefully controlled conditions. When the changes inside the grain are sufficient for the maltsters' requirements, heat is applied in the final stage in the malting process, using a specially designed kiln. The result, malt, has a moisture content of below 6.5%. The production of 1 tonne of malt requires, on average, 1.27t of barley, 1.18 Mwh of energy and 5 cubic metres of water.
There are five product groups:
Coloured malts (ranging from light to dark)
Roasted and peated malts
Malt made from other grains
The first process of malting is very similar to that which occurs in nature when the grain is sown in the ground. After cleaning, the soaking or steeping in water of the malting barley takes around one to two days with the objective of increasing the moisture content to about 44%.
During this stage, which can last for about five days, grain produces important enzymes which in brewing degrade starch to sugar.
Malt kilning lasts one to two days. Heat is used to stop germination, reducing moisture to about 5%, developing flavour as well as colour and producing a stable product. It is mainly variations in the kilning process that give different flavours and colours to the malted grain from which a wide range of European malts are produced. For instance, peat burning can be used during kilning to produce smoky (phenolic) flavours.
Finally, the rootlets (or culms), naturally produced during germination, are removed from the finished malt, and are nutritious and safe animal feed. Other co-products of the malting process are widely used in the animal feed industry, such as barley screenings, dust and detached husks.
A food ingredient
A multi-faceted food ingredient
Malt is made from malting grade cereals, usually barley or wheat, although occasionally other cereals such as rye may be used. Barley is usually the grain of choice for malting because it is bred specifically for the ability to process easily and generate a cascade of natural enzymes. These are used in later processing to convert starch (flour) into sugars and proteins into amino acids, all of which are highly nutritious when used in brewing, distilling or food manufacture.
A rich variety of different colours and flavours
Normal malt after kilning is termed ‘pale/pilsen malt’ and is relatively low in colour. It can be further roasted to create a magnificent palette of colour and flavour variations for use in brewing and food production. This increased range of malts is referred to as specialty malts. If malt is taken and roasted directly from the germination box (so-called called ‘green malt’) it produces sweet fruity and caramel flavours. If the kilned malt is further roasted it tends to generate more burnt roasted and bitter flavours and dark colours. The range of specialty malts allows for the creation of a great variety of different beers.
Malt can also be used to produce other food products. For example, it can be milled and turned into flours with various attributes such as generation of colour or tailor made to have high or low enzyme levels, depending on the application.
Malt extract is another product to deliver the unique attributes of malt. To produce malt extract, malt is mixed with hot water to digest the starch into a mixture of complex sugars and amino acids in a solution termed the ‘wort’. The wort is then concentrated into extract. In its simplest form, the extract can be used for brewing by dilution with hot water and the addition of yeast. In addition, it can also be used directly in the manufacturing of many food products, thanks to its natural characteristics.
A wholesome, nutritious product
Malt is low in fat, a source of fibre, complex carbohydrates (for slow release of energy), protein and vitamins and natural sugar constituents, which make it a very nutritious food and beverage ingredient. During malting, levels of vitamin B9 (folate) can increase up to 4 mg/kg. Just 100 g of malt can provide approximately:
10% of the daily recommended intake for vitamin B12,
44% of both vitamins B1 (thiamine) and B6 (pyridoxine),
34% of vitamin B2 (riboflavin),
88% of niacin and 80% of vitamin E
and in excess of 100% the vitamin B9 (folate) requirement (values may vary).