While six row malting barley was popular in the past, it has fallen out of favour.
“It used to be the exclusive malting barley type,” says Dr. Aaron Beattie, assistant professor and barley and oat breeder at the University of Saskatchewan.
In addition to tradition, reasons for this include that some brewers felt it imparted a certain flavour on the beer and that breeders were not focussing on breeding two row barley to the same extent as six row, meaning that two row barley varieties were less desirable for malt.
The largest initial difference between the two barley types was the amount of enzyme activity present to break down the starch in the kernels. However, over the years, breeders have improved the malting quality characteristics, called the malting profile, of two row varieties and therefore these varieties are now the most common.
The biology of the plant in terms of the head shape of two row versus six row barley differs. The kernels of two row barley tend to be more uniform than that of six row barley. Uniformity of kernels is important in the malting process, so two row varieties have a greater advantage.
According to Beattie, “six row barley is a barley type that is unique to North America,” and it currently has no use outside of North America. Within North America, only one major brewing company is still looking to use six row malting varieties; consequently, six row barley acres in Canada have dropped below 10 per cent of the total barley acres grown.
Even so, six row varieties still have a good agronomic fit in a lot of areas of the Prairies. Traditionally, they have been shorter and stronger plants, meaning that there was less chance of lodging. In the black soil zone or in areas that are a bit wetter, “six rows tend to perform a little bit better,” says Beattie. Farmers might want to grow six row varieties for this reason, but “these days it would be very hard to sell a six row malting barley for malting purposes.” †