2-row vs 6-row barley

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Not all barley is created equal. The way grains are arranged on the ear, whether the grain keeps its husk, and when the crop is sown all determine what a given barley is good for — and, above all, whether it can become malt for beer. Here's how the main types of barley differ, and why brewers and maltsters care.

2-row vs 6-row barley: the core difference

A barley ear is built from nodes, and at each node sit florets that can become grains. The number that actually develops is what separates the two great families of barley:

• 2-row barley (Hordeum distichum): only the central floret at each node is fertile, so the ear carries two rows of large, plump grains. It is the older type, closest to wild barley, and the gold standard for malting.
• 6-row barley (Hordeum hexastichum): three florets are fertile on alternating sides of each node, producing six rows of smaller grains. It is more modern and yields more grains per ear, but of lower individual quality for brewing.

(A rarer intermediate form, 4-row Hordeum tetrastichum, also exists.) Here is how the two compare:

Why brewers prefer 2-row barley

2-row barley is the most suitable for beer for several connected reasons. It produces more fermentable sugars and contains less protein, and it offers a better starch-to-husk ratio than 6-row. More starch relative to husk means more extract (sugar) per tonne; lower protein means a cleaner, less hazy beer and fewer off-flavours. In short, 2-row delivers better brewing properties — which is why it commands a premium and dominates the world's malting-barley trade.

Malting barley vs feed barley

Cutting across the 2-row/6-row split is the most commercially important distinction of all: what the grain is destined for.

• Malting barley is carefully selected grain — low protein, plump, with very high germination — grown from specific malting varieties and intended to be malted and brewed. Only malting varieties can legally and practically be turned into brewer's malt.
• Feed barley (also "caballine" or horse barley) goes to animal nutrition and has looser specifications. Roughly half of some countries' crops (including Argentina's) is feed barley and half malting.

The same field can yield either: a malting crop that fails to meet protein or germination specs is simply downgraded and sold as feed.

Covered vs hulless barley

Barley is also classified by whether the grain keeps its husk:

• Covered (hulled) barley keeps the husk (lemma and palea) fused to the grain. The husk is essential in brewing — it forms a natural filter bed during lautering — so covered barley is what's used for beer (and for animal feed).
• Hulless (naked) barley threshes free of its husk and is used mainly for human food: bread, pasta and other products.

Winter vs spring barley

Finally, barley is grouped by its growth cycle:

• Winter barley is sown in autumn (often late September/October) and harvested the following summer. Winter barleys dominate in countries such as France.
• Spring barley (called tremesina in some regions) is sown in spring for a shorter cycle. Much of the world's finest malting barley — including classic UK spring varieties — is spring-sown.

A quick history of the two types

2-row barley is the older form, appearing around 9,000 years ago in the Near East and closely resembling wild barley (Hordeum spontaneum). 6-row barley emerged later, roughly 6,000–7,000 years ago, with finds in Egypt and Mesopotamia. Both are diploid (2n = 14 chromosomes). For the full story, see our guide to malting barley.