Ingredients: Grain (1 of 3)

Grain is to beer as grapes are to wine.

All beer is made from grain, and the majority of that grain is malted barley.

Barley is ideally suited to brewing for several reasons:

• Barley contains starches that can be converted to sugar for fermentation
• Malted barley contains all the enzymes necessary to convert its starch into sugar
• Barley husks act as a filter during the brewing process

There are several types of barley, each one distinguished by the number of kernels, also called barleycorns, on the stalk of the plant. Only two- and six-row barley are used for brewing. Beyond the obvious physical differences in the plants, there are important differences between the kernels of two- and six-row barley. 

Enzymes 

Enzymes that convert starch into sugar are called diastatic enzymes.

Adjunct grains are grains used in brewing, such as corn or rice, that lack their own diastatic enzymes.

Six-row barley has more diastatic enzymes than two-row barley does. Selective breeding has decreased this difference, but the higher level of diastatic enzymes available in six-row barley make six-row barley preferable when large amounts of adjunct grains are used in brewing.

Protein

Six-row barley contains more protein (about 12 to 13.5%) than two-row barley (about 11 to 13%) does.

Higher protein often indicates that there is less starch available for conversion to sugar, and higher protein content can result in the formation of greater amounts of coagulated protein, called break, which must be removed to prevent hazy beer.

Dimethyl sulfide, commonly referred to as DMS, forms as proteins break down. Having more protein makes six-row barley more susceptible to the formation of DMS, which can produce an off-flavor in beer.

DMS will be covered in detail in the off-flavor section of this study guide [link pending]. 
 
Starch

Two-row barley contains more starch than six-row barley, so more sugar can be extracted from two-row than from six-row. This means that for equal amounts of barley, you can make more beer from two-row than from six-row.

Husk

Six-row barley has a thicker husk than two-row barley does, and this thicker husk is high in tannins, which can cause haziness and can impart an astringent taste.

Size

Two-row barley has large, uniformly sized kernels. In six-row barley, some rows have kernels that are a different size than kernels in other rows. When milling barley, it is much easier to get uniformly sized ground grain, called grist, if the kernels are all the same size. 

Cost

Two-row barley tends to be more expensive than six-row barley. Six-row barley yields more grain per acre than two-row barley.

Climate

Two-row barley has better drought tolerance, and prefers cooler climates than six-row barley does. Most six-row barley is grown in North America. 

Here is a list of major barley producing countries.

The takeaway:

Two-row barley has fewer enzymes, less protein, more starch, and a thinner husk than six-row barley.

Six-row barley has more enzymes, more protein, less starch, and a thicker husk than two-row barley does.



For Further Research:

Brewer's Market Guide
BYO Magazine - Dear Mr. Wizard
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