Barley is the world's oldest grain, proven by discoveries in ancient cities located in the Mideast and North Africa. It has been cultivated for about 8,000 years, and today is the world's fourth largest cereal crop.
Barley as a food is most commonly identified as pearl barley, traditionally used in soups. Pearl barley has many other food uses, such as casseroles, pilafs or salads. Barley flour and milling fractions such as bran, middlings, shorts and "red dog" can also be used for baked products and breakfast cereals.
There are many genotypes of barley that exhibit a wide range of physiological and morphological characteristics that somewhat determine the end use. A major factor affecting total dietary fiber in barley is the nude gene (nn) which controls the adherence or non-adherence of the hull to the kernel. This separates all barleys into one of the following types:
- Covered, or having a hull that adheres tightly to the kernel;
- Hull-less, sometimes called "nude," because the hull falls off the kernel, as with wheat, during harvesting.
If the yield increases due to the presence of the hull and demand for this type in malting, most common barleys are of the covered type. However, there is growing interest in the hull-less type, which is very adaptable for human food products causing the entire grain to be used without pearling.
Barley malt is an important ingredient for beer production. It is also used in extracts and syrups for adding flavor, color or sweetness to commercially prepared foods such as cereals, baked goods, confections and beverages.
Barley malt is made by soaking and drying barley kernels. The kernels are then allowed to germinate or sprout in a controlled environment.
The malting process converts raw grain into malt. The malt is mainly used for brewing or whiskey making, but can also be used to make malt vinegar or malt extract. Various grains are malted, the most common grains used are barley, sorghum, wheat and rye.
There are a number of different types of equipment that can be used to produce the malt. A traditional floor malting germinates the grains in a thin layer on a solid floor, and the grain is manually raked and turned to keep the grains loose and aerated. In a modern malt house the process is more automated, and the grain is germinated on a floor that is slotted to allow air to be forced through the grain bed. Large mechanical turners keep the much thicker bed loose with higher productivity and better energy efficiency.