Building a Grain Bill

All grain home brewers will first consider their grain bill, an important factor influencing style, flavor, aroma, body, and alcohol by volume (ABV). Each grain added into the final product has a specific purpose. Base malts provide the majority of fermentable sugars whereas specialty malts and other brewing sugars influence more flavor and aroma. The combination of these grains helps to define the different beer styles. Learning how to combine and use the various grains will not only help you to recreate classic styles, but it will allow you to create truly unique beers.

Base malts include but are not limited to: two-row, six-row, pale, pilsner, Maris Otter, Munich, or Vienna. According to the style and wanted characteristics of beer being brewed, they typically consist of 80 to 100% of the grain bill. Base malts have different characteristics, but their main purpose is to provide the majority of fermentable sugar. Out of the base malts, pilsner is the lightest in color and flavor whereas Vienna and Munich are the strongest in color and flavor. Maris Otter, two-row, and six-row fall in between although they have different properties.

While base malts add the majority of fermentable sugars, specialty malts add flavor, color, and body. Like the base malts, each style of beer has certain proportions of specialty grains that are commonly used. There are many types of specialty malts available. Examples include: aromatic, black barley, rice, chocolate, crystal, wheat, victory, rye, and rauch. Specialty malt characteristics range from light to dark in both flavor and color. As for their contribution to body, some specialty malts help aid in head retention and body; others will have the opposite effect by thinning out the body and lowering head retention. Very few of the specialty malts are used to increase the fermentable sugars, but corn and rice are exceptions to this.

Other brewing sugars can also be added to beer, but typically should be no more than 10 percent of the fermentable sugars. Examples are: honey, brown sugar, lactose, fruit, raw sugar, and maple syrup. Most sugars have plenty of sucrose which is highly fermentable (although some have none). Unfortunately they also have other sugars that may not be fermentable. These other sugars can disrupt fermentation or impart large amounts of flavor or color. Learning the flavors these sugars impart will come with experimentation and trying commercial brands that use them.

Deciding on an official grain bill can be difficult to determine. Once the type and percentages of each grain are decided, focus has to be turned to target gravity and mash efficiency. Mash efficiency is somewhat difficult to determine. Even an experienced home brewer can sometimes be surprised by their mash efficiency or lack of efficiency.  Instead of worrying too greatly on mash efficiency, try focusing on hitting the target gravity (although “Designing Great Beers” by Ray Daniels has tons of great ideas for calculating the mash efficiency and target gravity).

Each style has a specified range for the target gravity and by hitting within these ranges, the results are much better because the gravity influences the ABV and the balance between bitterness and sweetness. To hit the target gravity, always have a hydrometer at hand while brewing. Assess the gravity of the wort during the mash, after the mash, after lautering, and while boiling. By assessing the gravity throughout the brewing process, measures can be taken to hit your target gravity even if the brew isn’t on target. For example, if the gravity is lower than expected after the mash and lautering, extra boiling time will produce a smaller volume of beer or add more fermentable sugars; if the gravity is too high, dilute the wort or remove part of the wort. These solutions are simple and can typically be done throughout the brewing process with care. No one wants to get to the end of the brewing process to relieve they have missed the mark completely. At the end, it becomes more difficult to make large changes.

Learning the brewing process is largely based on trial and error so keep good notes throughout the brewing process. Looking back on notes of previous brews, it’s usually easy to see where things don’t quite add. To learn the flavors and aromas of the various malts, taste the wort after the mash, chew on a piece of grain, or make “teas” with the grain. Entire books are written on each style of beer and should be referenced when trying to recreate them or making a unique representation of one. These books will give far more insight into the guidelines of each style than this article can alone. Cheers to learning the science of brew through experience and the love of beer!