Single-Malt Brewing

March 1, 2012 By K. Florian Klemp

To the novice, brewing can seem a bit daunting, but, as is the case with any hobby, that initial hesitation is replaced by confidence via experience. That same experience makes the task of brewing simpler, even as the process becomes seemingly more complicated. Brewing also gets the intellectual and creative gears turning, opening up a world of endless possibilities that can be taken to the homebrewery. Well-seasoned brewers often craft beer in rather Spartan fashion, relying on the interplay of medium and technique rather than the complication of an extensive list of ingredients. Brewers are now touting single malt and, even more impressively, single malt and single hop (SMaSH) beers. Homebrewers are especially keen to this idea, as it is not only a means to simplify a recipe (and ingredient list) but serves to test one’s brewhouse mettle in several ways. There is a myriad of base malt suitable for this approach and a number of brews that can be cobbled from each. Both classic styles and experimental brews are possible with basic attention to mash and kettle parameters in conjunction with a singular base malt. Minimalist brewing at its finest.

Why Single Malt?

Single malt brewing is not only a challenging and enlightening way to brew, but also has a direct connection to anachronistic ancient brewing practices. Professionals more often than not make historical beer styles as they present a safe perspective and tangible reference point, but most of the brews are based on styles that emerged after the advent of the specialty malts. Single malts capitalize on the properties of a particular malted barley, but also harken to a time when many brews were made from one type of malt. Those from Continental Europe were even given the name of the city in which they were developed, but also came to represent the signature style or characteristics of that city’s beer.

Pilsner, Vienna and Munich malts are examples, all of which are synonymous with the 19th century brews that were developed in each city, each beer bearing a distinctive color. Porters of the 18th and 19th centuries were often made from a single kilning, bringing their dark brown color and rough-hewn character to the brew. The rauchbiers of Bamberg are made with various measures of smoked malt, but some are single malt brews, made to the specifications of the brewery, often in-house.

English pale ale, American pale and mild ale malts are designed to provide a firm backbone in traditional ale recipes, but have plenty of delicate malty flavor to use without augmentation. Of course, from a pure technical point of view, brewing single malts allows the brewer a chance to examine the unique characteristics of the selected base malt while learning to shift the expression of that malt through further manipulation of mash and kettle.

The Mash

Anyone who does all-grain brewing knows the effect that mash temperature has on the mouthfeel and fermentability of the wort and, ultimately, the balance and texture of the beer. This is especially important with single malts because there are no bodybuilding specialty grains to fall back on. The ratio and interplay of alpha (dextrin) and beta (maltose and other fermentables) amylase is dependent upon the temperature of the mash, and is, next to the malt type, the most crucial brewing decision. Single malt kölsch versus single malt Munich helles may have mash temperature as its only prefermentation variable, with a difference of 4 or 5 degrees Fahrenheit between the two.

The Kettle

Of the many conditions that can affect the color and flavor of wort post-mash, the way in which the boil is executed can have the greatest influence. Degree of caramelization and melanoidin formation can be controlled rather expertly in the kettle by the duration, intensity and timing of the boil. Malliard reactions are a convoluted series of chemical changes in the presence of heat that causes browning and the combination of sugars and amino acids into melanoidin complexes. During this process, there are hundreds of compounds created that have flavor attributes different from the original components. Baked and roasted foods are examples of important culinary transformations. Vienna and Munich malts can do the same thing during the toasty kilning.

Caramelization is the darkening, and consequential flavoring effect that heat has on sugar, and can also be enhanced in the kettle. Caramel and melanoidin formation occur during any boil to some degree, but the key is to either minimize (pale beer) or maximize the formation (dark beer) for the desired effect. The best way to maximize is to intensely boil the first couple of gallons of wort until a noticeable darkening occurs. I like to do this for about 15 minutes before continuing the runoff. The first runnings are the strongest, increasing the interaction of the sugars and amino acids. Alternatively you can darken and concentrate the wort with a longer or more intense boil or both. For bocks and barley wines, start your boil after collecting two gallons of wort. Boil during the entire running of the wort, and another l hour during the hop additions. This prolonged boil of 2 to 3 hours will move your light-colored beers towards amber and your amber beers towards brown. It will contribute a host of flavors and complexity, and make efficient use of your malt.

The Recipe

The versatility of base malts will come as quite a surprise to those who haven’t contemplated making single malt brews before. The variety of these malts combined with the dozens of hop cultivars and yeasts and paired with deft mash and kettle technique leads to a virtual explosion of possibilities. Even within the realm of classic styles, the types of beers that can be made from Pilsner malt, for example, are extraordinarily broad. Of course, some combinations of the three base ingredients are seemingly made for each other. English pale ale malt, East Kent goldings hops and a characterful English yeast is a sublimely simplistic trinity. Likewise, Vienna malt, Halletauer or Tettnang hops and Bavarian bottom-fermenting yeast will make any lover of amber lagers swoon. SMASH beers such as these are the zenith of single malt brewing, but single malts are also an excellent way to demonstrate hop profiles or yeast imprint. Below are a few suggestions using the common base malts and classic beer styles that can be made from each. All of the base malts mentioned below are equipped with enough diastatic power to convert themselves over the course of a normal mash period of one hour (Lovibond specs are approximate). Even malted wheat (2.0 to 3.0°L) offers the opportunity for a single malt beer, but go heavy on the rice hulls in the mash to aid lautering.