Row Number: 2-Row vs 6-Row
The most fundamental classification in malting barley is based on the number of fertile floret rows on the spike. This distinction has major consequences for grain composition, enzyme activity, and suitability for different brewing styles.
2-Row Barley (Hordeum vulgare subsp. distichon)
In 2-row barley, only the central floret of each triplet is fertile, producing one grain per node on alternating sides of the rachis. This results in larger, more uniform kernels and a lower overall protein content relative to 6-row types. The husk-to-kernel ratio is favorable for malting, and the starch content is high, giving strong extract potential.
Two-row malt is the standard for European lager and ale brewing. It produces malt with high extract, moderate diastatic power, and a clean, smooth flavor profile. The low adjunct-conversion capacity is not an issue in all-malt brewing systems.
6-Row Barley (Hordeum vulgare subsp. hexastichon)
In 6-row barley, all three florets of each triplet are fertile, resulting in six rows of grain along the spike. This produces more grains per head but smaller, less uniform kernels with higher protein content. Importantly, 6-row barley has significantly higher diastatic power โ more amylase enzymes โ which makes it valuable when adjuncts such as corn or rice are added to the mash.
Six-row malt is predominant in North American brewing traditions, where large proportions of adjuncts are standard. The high enzyme activity compensates for the lower starch content of the adjuncts and converts them efficiently during mashing.
| Characteristic | 2-Row | 6-Row |
|---|---|---|
| Kernel uniformity | High โ large, even kernels | Moderate โ smaller, variable kernels |
| Protein content | Lower (9โ11.5%) | Higher (11โ14%) |
| Extract potential | High (80โ82% dry basis) | Moderate (75โ79% dry basis) |
| Diastatic power | Moderate (100โ150ยฐL) | High (160โ300ยฐL) |
| Husk ratio | Lower โ favorable for mashing | Higher |
| Adjunct conversion | Limited capacity | Excellent capacity |
| Primary markets | Europe, Australia, South America | North America |
| Typical use | All-malt lagers, ales | Adjunct lagers |
Growth Season: Winter vs Spring Barley
Barley is grown in two primary seasonal types based on the vernalization requirement โ whether the plant needs a cold period to progress from vegetative to reproductive growth.
Spring Barley
Spring barley is planted in late winter to spring and harvested in summer or early autumn. It does not require vernalization and completes its life cycle in 80โ120 days depending on variety and climate. Spring barley tends to produce lower yields than winter types but often achieves better malting quality โ particularly lower protein content โ in appropriate climates. It dominates malting programs in Scandinavia, the British Isles, Canada, Australia, and Argentina.
Winter Barley
Winter barley is planted in autumn, overwinters as a vegetative plant, and completes grain fill the following summer. The extended growing season and deeper root development typically produce higher yields than spring barley. However, winter barley tends toward higher protein content, which can be a challenge for malting specifications. It is widely grown in France, Germany, Eastern Europe, and the UK, with dedicated winter malting varieties developed to meet quality thresholds.
| Characteristic | Spring Barley | Winter Barley |
|---|---|---|
| Planting time | Late winter / early spring | Autumn |
| Harvest | Summer / early autumn | Early summer (ahead of wheat) |
| Growing period | 80โ120 days | 240โ280 days |
| Yield | Moderate | Generally higher |
| Protein tendency | Lower โ often better for malting | Can be higher โ managed by N timing |
| Cold hardiness | None required | Essential |
| Main malting regions | UK, Scandinavia, Canada, Australia | France, Germany, Eastern Europe |
Husk Type: Covered vs Hulless Barley
Covered (hulled) barley retains its husk firmly attached to the grain after threshing. This is the standard form for malting because the husk provides filtration during mashing and protects the kernel during steeping and germination. Hulless (naked) barley has a loose husk that falls off at threshing. While hulless types are nutritionally interesting for food and feed uses, they are challenging for malting because the unprotected grain is more susceptible to damage and microbial attack during processing.
Note on hulless malting: Research programs are developing hulless malting barley varieties for specific applications, including distilling and specialty malt production. However, covered barley remains the industry standard for conventional malting operations.