Originally By Tony Ackland
Most of the current barley varieties used for malt whisky are two-row, as opposed to six-row (which is indigenous to countries such as Sweden, Norway and Finland, where it is the basis for Finlandia vodka). This numerical distinction refers to the fact that the ear (or 'head') essentially contains two rows of seeds, while six-row barley contains six rows of seeds. An ear of two-row barley contains a total of around 24 to 34 seeds, depending on the variety and environmental conditions. Those with higher totals can have smaller-sized seeds, while varieties with lower totals may have larger-sized seeds, which pretty much evens it all out. Moreover, the amount of seeds is not as important as the overall weight of the grain. Another distinction to draw is between winter barley (sown in August to September and harvested in late July to early August), and spring barley (sown in March to early April and harvested in August to September).
While both can offer the same flavour and level of quality, spring barley is a standard choice in the industry. This is despite the fact that agricultural yields are typically slightly lower, between 2 and 2.75 tonnes per acre, compared to winter barley at around 2.5 to 3.5 tonnes per acre. However, as spring barley usually has higher levels of starch and lower levels of nitrogen, the yield of alcohol is higher which clinches it for the distiller. Barley is generally cultivated along Scotland and England's eastern coastline, locations that offer the most favourable conditions. How influential any element of terroir may be, in comparison to the barley variety cultivated, is another consideration. As a barley variety that may inherently give a good level of starch also depends on the climate to achieve this potential, it's generally considered to be a fairly even split between the barley and the climate. While annual weather conditions can affect starch and nitrogen levels, some barley varieties are better at surviving adverse weather, and are more resistant to certain infections. This explains why another school of thought is that the barley variety is slightly more significant than climate.
Scotland's milder climate, with long daylight in summer, can certainly be a great advantage. Steady amounts of rainfall are ideal after sowing spring barley, while sunshine is required when it flowers in late June. Flowering lasts about a week, and the seeds begin to form after pollination occurs (conveniently, barley is self-pollinating).
Although lower levels of nitrogen are ideal for the distiller (it's a straightforward formula, the less nitrogen, the higher the starch content), nitrogen is added to the soil, together with phosphate and potash. These are combined in a compound fertiliser, usually applied a couple of times, at sowing time and mid-way through the growth cycle. The farmer calculates the mineral levels in the soil, and how they need to be supplemented, with each element of the fertiliser performing a strategic role. Nitrogen promotes growth and the production of green pigments which are used for photosynthesis, while phosphate and potash benefit the roots.
Photosynthesis (which occurs during daylight) starts to build up starch granules within the seed, together with rising levels of nitrogen. Starch continues to develop until the grain is harvested, with a straightforward hierarchy emerging: the largest starch granules being the oldest. A ripe grain contains numerous larger and smaller starch granules, with the aim of the plant being solely to produce seeds that ensure the subsequent generation of barley. Different barley varieties are termed 'early' or 'late', depending on the date of maturity, Chariot being early and Optic late. The difference between early and late can be a case of one to two weeks, which may not sound long, but this is a significant time-span for the farmer (particularly in September when the weather is certainly less than reliable).
Once harvested, most maltsters subject the barley to indirect air drying, using a system of heated pipes, like central heating. The other option is direct air drying, when air is heated by a flame created by a furnace. Either way, barley is dried to a moisture content of up to 12%. At this point the grain is dormant, a schedule imposed by nature to ensure that grains begin growing during the appropriate season.
As barley can only be malted once ready to germinate, the length of dormancy is a relevant factor. A traditional variety such as Golden Promise can be dormant for around two months, whereas Optic is ready for action after four to six weeks.
Emerging successfully from dormancy also depends on appropriate, watertight storage at the right temperature, which enables barley to be stored for up to a year, or longer (though supply and demand essentially determine the length of storage).
The main barley varieties currently used are Optic, Chalice and Decanter, which were developed during the 1990s. Optic took the top ranking from the previous leader of the pack, Chariot, in the year 2000. Chariot had commanded 40 to 45% of the market since the mid-1990s, but as it's a fast-moving business Chariot is now fading from the scene. In fact, the rate at which newer varieties replace earlier generations has become more rapid, and is currently around three to five years. This compares to Golden Promise (originally developed in the 1950s) which reigned supreme from the mid-1960s to the mid-1980s.