I was sitting in the shade enjoying the lovely Belgian ale on tap when someone asked me what I thought about two-row barley. I am lucky enough to live in a region where I can get either six-row or two-row most of the time, so I adjust my grain bill to the recipe at hand, rather than the other way around. Many brewers prefer two-row barley for its greater extract value; on examination that’s interesting, since the difference is 1 to 2 percent, hardly noticeable at the homebrewer level. I generally prefer two-row, but I’m not sure I could quantify why, since both types appear in many of my favorite beers. Maybe we all think two-row is just more chic.
Two-row or six-row? It’s a very American question. Most of the rest of the world uses six-row barley only for livestock feed, not for beer. I thought six-row barley had been bred especially to increase output, but it turns out to be a naturally-occurring result of a pair of mutations, one dominant and one recessive. Both two-row and six-row barley have been around for a long, long time.
Breeding efforts of the last half-century have reduced and perhaps functionally eliminated most of the differences between the two types of barley. Economies of scale at big breweries make many of their differences moot. There are still distinctions between kernel size, extract, protein and enzymes—all this information can be found online, depending on your tolerance for technical detail.
barley
Morphology:Two-row barley kernels tend to be symmetrical and of an even size, so they tend to absorb water at about the same rate, and germinate and dry about the same; they’re also easier to grind in two-roller mills. Six-row barley has a symmetrical center, but the two lateral rows of kernels are a little shorter, thinner, and twisted slightly. Maltsters often separate each lot of six-row barley into several kernel size fractions since they differ in water uptake and germination speed. A six-roller mill with a screening system (often used at major breweries) can make grist of the differently sized kernels. For homebrewers, a larger grist particle size dis
Malting: Scott and Cherie Stihler have a straightforward description of how a malting floor works on their site. While they acknowledge malting floors have mostly given way to big revolving drums, I agree with them that it’s easier to understand the process if you think in terms of a malting floor. Distribution is important when you’re lautering, but big breweries use a mash filter, with a filter cloth, shallower grain bed, and high pressures, so it makes almost no difference to them.
Once malted, the plumper kernels are generally re-blended and used as brewer’s malt. The thinner ones have higher enzymatic activity and may be sold as distiller’s malt. The thinnest kernels are sold as feed.
In the 1960s, a six-row cultivar called Larker significantly reduced the size difference between kernels (Larker’s name was coined from “large kernels”). Since then, new cultivars have supplanted Larker (which is no longer used as a malting barley). Plumpness in six-row barley continues to increase, but two-row varieties are still plumper. Why do we care about plumpness? Plumpness is a moderate indicator of malt extract yield, though these days six-row barley’s yield is only 1 to 2 percent lower than two-row.
Six-Row Pros:
It has more protein, less starch, and a thicker husk than two-row.
Higher protein levels may help speed conversion to fermentable sugars. This is important to homebrewers using high mash-in temps; more conversion would take place than otherwise.
Six-row has higher enzyme content for converting starch into fermentable sugars. More enzymes means it can convert adjunct starches (which lack or are deficient in enzymes) during mashing. Offset this with more (less expensive) adjunct grain use, and you know why so many large breweries use six-row.
Six-row is less expensive per pound, and allows further cost cutting through the higher use of inexpensive adjuncts to offset the high protein levels.
Supplementing two-row malt with some six-row malt might increase extraction, conversion time, and fermentability, particularly if you have a high percentage of adjuncts.
Six-row yields more per acre.
Those thicker husks improve the filter bed for lautering.
Enzyme and protein levels are high enough that a brewer probably doesn’t want to use six-row barley exclusively in a recipe. (Adjunct grains are cheaper.) Unmalted cereals (corn and rice) are often mixed in with malt to compensate for the higher protein levels in six-row barley—up to 40 percent of six-row grist can be adjunct. New malt strains mean adding adjuncts is no longer necessary, but it’s economical and, in the case of some large breweries’ beers, traditional.
Six-Row Cons:
Six row is more susceptible to the formation of dimethyl sulfide, a process begun through protein breakdown in malting. Some DMS is acceptable in some beer styles, but too much may contribute to a cooked