If you have the imagination, beer can be brewed from pretty much any grain, but in Western society barley is the main grain used in beer. In its malted form, barley is usually responsible for all of the colour and alcohol in addition to much of the flavour of beer; however wheat, other grains, and sugars can have some say too.
Barley is very equipped for making beer. It is an astounding bundle of starch, proteins, enzymes, and other elements. This humble grain holds a huge range of prospects which we can transform into a bewildering variety of different beers. A barley seed is a dense bundle of biochemistry, with specific features, behaviours, and needs, all of which we must appreciate if we want to get what we want out of it.
Barley is a grass in the genus Hordeum and wheat is closely linked to it evolutionarily, as is spelt—all three of which have been used for brewing at various times and places throughout history. Barley was amongst the first grains domesticated in the Middle East around twelve thousand years ago. Early agronomic people vigilantly selected the type with the best qualities, replanting the finest seeds, and eventually generating strains perfectly matched for brewing beer: with low protein, lack of gluten (as a pose to wheat), and kernels that separated with the husks intact. This is a pretty strong sign that early people were brewing forms of beer; barley which possesses these qualities is not all that useful for bread or anything else but gruel, and who wants gruel?
Barley is categorized by the number of kernels at each location along the stalk: two-, four-, or six-row. The earliest form of barley is two-row, Hordeum distichum. Due to its light flavour and low protein content, two-row is still the preferred choice, particularly in all-malt beers. Six-row forms have a higher amount of husk and protein both of which are detrimental when brewing if used in large amounts as they can add haze and acidic flavours. Due to the high proporptions of enzymes present in six-row malt, it’s usually used for brewing beers with rice/corn additions, as these lack enzymes. Belgian witbier utilises six-row malt, the traditional recipes contain up to 50 percent unmalted wheat and oats, which also have an absence of usable brewing enzymes. Four-row types (Hordeum tetrastichum) also exist but are rarely used.
Six-row barleys tend to be found in hot climates, North Africa, India, Mexico, and the Upper Midwest of the United States are excellent growing regions for six-row barleys. Two-row barleys are usually found in cooler regions such as the American Northwest and northern Europe. The protein content, a vital brewing variable often reflects the wealth of the soil. American barley varieties, both two- and six-rowed, contain a higher amount of protein than those found in Europe, and Australian and South American forms have even lower protein contents due to the thinness of the soil in these regions.
There are variances in nutritional content by strains and growing locations; however they tend to be far less important than in a beverage such as wine. Some barley types such as England’s well-known Maris Otter, do display terroir, the unique expression of locality, however most strains are very much a product, selected for yield, disease resistance, and other agricultural qualities as well as brewing value. The maltster has a much more impact on the overall malt than the soil or weather does.