The first and very critical step in creating quality malt is steeping. This is when the barley grain kernel that has been sorted and cleaned is brought to life with water and oxygen. This is done by immersing or “steeping” the grain in water, followed by an air rest period that allows the water content of the grain to increase. The raw barley alternates between submerged and drained until it increases in moisture content from about 12% to about 44%.
The absorbed water activates naturally existing enzymes and stimulates the grain embryo to develop new enzymes. The enzymes break down the protein and carbohydrate matrix that encloses starch granules in the endosperm, opening up the seed’s starch reserves, and newly developed hormones initiate growth of the acrospire (sprout). The water temperature and aeration are vital for producing high-quality malt. The steeping process can vary with grain type and size but typically occurs over a period of 24-48 hours.
The steeping is complete when the barley has reached a sufficient moisture level to allow a uniform breakdown of starches and proteins. One visual indicator that the maltster uses to determine the completion of steeping is to count the percentage of kernels that show “chit”. Raw barley that has been properly steeped is referred to as “chitted” barley”, the “chit” being the start of the rootlets that are now visibly emerging from the embryo of the kernel.
The second step is to continue the germination process that started in steeping. The chitted barley is transferred from the steep tank to the germination compartment. Here, growth and modification of the grain occurs. From the outside of the grain, rootlets emerge from the kernel, and within the outer husk a shoot – or acrospire – grows. Modification is the breakdown of protein and carbohydrates and results in the opening up of the seeds’ starch reserves.
This process typically takes 4-6 days and results in what is called “Green Malt.” To achieve a high quality and consistent germination process, our maltster controls temperature and moisture levels with regulated airflow and uniform water spray. To avoid grain clumping, non-uniform heating, and varying rates of germination, the grains are separated with periodic rotation using turners keep the bed from compacting and rootlets from growing together, or felting.
Even with modern equipment and this structured approach, the degree of modification is still gauged by our craft malster with his eyes, his sense of smell, and with his hands. Malting truly is part art and part science.
The third and final step in the malting process is kilning. Convection heat treatment dries the green malt to prevent further germination. If germination continued, the kernel would keep growing and all of the starch reserves needed by the brewer would be used by the growing plant.
For most malts, moisture is initially removed from the germinated grain – this is called Withering. Additional drying further reduces the moisture content and prepares the malt for flavor and color development. Other important results achieved during the kilning process include enzymatic activity and friability.
It is the controlled variations in this step that produces the wide range of malt colors and flavors used by brewers in crafting their unique and distinctive ales and lagers.
Base malts are kiln-dried. typically with a finish heat of 180-190° F for 2-4 hours. This develops flavors ranging from very light malty to subtle malty.
Specialty malts are dried in a kiln at higher temperatures for longer periods of time, roasted, or both. Varying the moisture level and time and temperature of drying develops the flavor and color characteristics of each specialty malt.
Roasting is done if required in an additional stage. Using Great Western Malt (GWM) as an example, GWM Malt, grain spends 34-46 hours in steep tanks where we aim for a target moisture of 42-44%. The grain is transferred to germination which lasts for around 4 days in Wanderhaufen style streets. This is a semi continuous moving batch germination process. Once germination is complete, the green malt is then transferred to the roasting drum.
The roasting takes place in two roasting drums. The average roasting time is 2 ½ – 3 hours with an air on temperatures of up to 460˚C. Their roasters can take a batch size of 2.4 – 3.5 tonnes. The roasted malt is then transferred to the cooler and spends 35 – 60 minutes there in order to drop the temperature to <15˚C and fix the color and flavor compounds. The malt is analyzed before storage and thereafter awaits delivery to customers.
The Egyptians were brewing beer in 4000 BC and artifacts in the Cairo museum show that it had already evolved into a disciplined technology by the third millennium BC. Originally malting was carried out on a small scale in small farms by steeping sacks of barley in streams or troughs, germination would then occur in the sack or trough and it would be kiln dried over a stove.
The making and selling of malts was often controlled, in Nurnberg in 1290 only barley was allowed to be malted, while in Augsberg between 1433 and 1550 beer was only to be made from malted oats. In England malt carried a tax for many years until 1880. By 1588, European settlers in North America were trying to make beer from malted maize. Beer can be brewed from a range of cereals, but by the 17th century beers brewed from barley malt predominated in Europe.
By the 17th century floor malting was the method being used to malt larger quantities. Floor malting was the only method of malting in use until the 1850’s. In floor malting, steeped barley is laid in piles on tiled or concrete floors and allowed to build up some heat and begin growth. The malt is turned manually with wooden shovels to reduce heat build up and aerate the grain. This method is very labor intensive and time consuming.
By the 19th century the development of large breweries led to the industrialization of malting and an increase in the size of production units. Pneumatic malting was developed and reached commercial success in the late 1800s. Two Belgian malting engineers; Galland and Saladin are considered to be the fathers of the modern malting equipment. Galland introduced the first aerated rectangular boxes in 1873 and Saladin introduced turning machines in 1880s. Saladin boxes are in common use today.
With the expansion of trade and the discovery of the New World, making beer from barley malt spread across the globe. Currently, approximately 1,400 million hectolitres of beer are brewed annually around the world.
Sources: Malts and Malting: Dennis E Briggs, 1998; Malt: A Practical Guide from Field to Brewhouse: John Mallett, 2014; https://www.greatwesternmalting.com
All grains start life as whole grains. In their natural state growing in the ﬁelds, whole grains are the entire seed of a plant. This seed (which industry calls a “kernel”) is made up of three key edible parts – the bran, the germ, and the endosperm – protected by an inedible husk that protects the kernel from assaults by sunlight, pests, water, and disease.
The bran is the multi-layered outer skin of the edible kernel. It contains important antioxidants, B vitamins and ﬁber.
The germ is the embryo which has the potential to sprout into a new plant. It contains many B vitamins, some protein, minerals, and healthy fats.
The endosperm is the germ’s food supply, which provides essential energy to the young plant so it can send roots down for water and nutrients, and send sprouts up for sunlight’s photosynthesizing power. The endosperm is by far the largest portion of the kernel. It contains starchy carbohydrates, proteins and small amounts of vitamins and minerals.
WHOLE GRAINS ARE HEALTHIER
Whole grains contain all three parts of the kernel. Reﬁning normally removes the bran and the germ, leaving only the endosperm. Without the bran and germ, about 25% of a grain’s protein is lost, and are greatly reduced in at least seventeen key nutrients. Processors add back some vitamins and minerals to enrich reﬁned grains, so reﬁned products still contribute valuable nutrients. But whole grains are healthier, providing more protein, more ﬁber and many important vitamins and minerals.
Whole grains may be eaten whole, cracked, split or ground. They can be milled into ﬂour or used to make breads, cereals and other processed foods. If a food label states that the package contains whole grain, the “whole grain” part of the food inside the package is required to have the same proportions of bran, germ, and endosperm as the harvested kernel does before it is processed.
FINDING WHOLE GRAINS
Whole grains currently make up far less than half of all grains on supermarket shelves (though growing every day!). At a time when health professionals urge consumers to eat at least half of their grains as whole grains, our Whole Grain Product Finder can make ﬁnding whole grains a snap.
Barley grown for brewers malt is called malting barley, as opposed to feed barley, and is divided into two general types; 2 Row Barley and 6 Row Barley. The most obvious difference between a head of 2-row barley and a head of 6-row barley is the arrangement of the kernels when the head is viewed down its axis. Brewers don’t make a big deal about 2-row versus 6-row barley based on the appearance of the barley head, however. The significant differences are found upon closer examination.
In general, 6 Row Malted Barley has more protein and enzyme content than 2 Row Malted Barley, it is thinner than two row malt and contains less carbohydrate. There are also flavor differences between 2-row and 6-row and it seems that most brewers feel 2-row malt produces a fuller, maltier flavor and 6-row malt produces a grainier flavor in the finished beer. The interesting fact about 6-row barley is that it is only grown in North America.