Beer 201 today.
You have, no doubt, heard us talk about two-row and six-row malted barley. A common question that we get is, "what is the difference" and/or "what difference does it make"? If you think of a shaft of barley (such as the one to the left there), you can imagine the grains grow around in orderly rows around the shaft. Well, some are more orderly than others, and some varieties have bigger grains than others.
Think about it this way: a shaft of barley is only so big; it can only support so many grains. The grains are either (relatively) bigger, but fewer, or the grains are smaller but more numerous. Six-row barley is, as you might guess, the smaller but more numerous grains (there are six rows of grains on the shaft, sort of); two-row barley grains are bigger and less numerous.
Well. Using barley in beer works like this: the grains are steeped in water to cause them to swell and begin to germinate. This early-germination process converts the starches in the barley to sugars that are then fermented to make alcohol. This germination process is halted before it completes to optimize the sugar content. This steeping and halting process is called "malting" and barley that has been steeped and dried is called malted barley. Two-row barley has fewer protein and more starch available for conversion. Six-row barley has more protein and less starch available for conversion.
This means that if you have the same amount of six-row and two-row malted barley, there will be less sugars and more proteins/husky content in the six-row than in the two-row. Or, stated alternatively, the two-row will contain more sugar and less protein than the six-row. This, in turn, means that beer made from two-row malted barley will ferment "better" and have less of a "grainy" or "husky" taste. Or, again stated in the alternative, six-row malted barley will be less fermentable and more "husky"/"grainy" in flavor.
Two-row malts are favored in traditionally English, German and Belgian styles. Six-row malts are frequently found in American and French styles. In American styles these six-row malts are frequently combined in the grain bill with corn or rice. Moreover, two-row barleys do not grow particularly well in Wisconsin soils and climates; however, six-row barley does grow fairly well here.
There's a myth and perception that somehow two-row are "superior" to six-row; but this subjective judgment is exactly that. French biere de gardes, some of the most sophisticated beers you can find, are traditionally made with six-row barley. The huskiness, the graininess, can be sublime if allowed to shine and not overpowered by assertive hop or other grain flavors.
While far from a definitive statement on malting and barleys, I hope you've learned something here. This is a subject that gets quite scientific (and beyond my ability to relate to you in a way that I can make understandable) quite quickly and starts to introduce the reason why brewers are skilled, artistic, scientists and not just mad alchemists.