Grain to glass flavor

by Tamara Scully
Every brewer knows the importance of the correct malt in crafting his brews. And every maltster knows that the quality and properties of the grain they begin with significantly impacts the malt. Both the malting and brewing processes rely on chemical reactions, and those reactions also have an impact on the final flavor of the malt or the beer. Correlating grain, malt and beer flavor from grain to glass isn’t a simple process.
“Flavor is the most important measure of quality,” Lindsay Barr, Sensory Specialist at New Belgium Brewing said. “We can take all the different analytical measurements in the world and still not know what the product is really going to taste like.”
Instead, training a sensory team to evaluate flavor profiles of malt and beer, much like wine connoisseurs evaluate wine, is a valuable method for assessing quality. Flavor impacts will affect the decision making process at the brewery, from selecting barley varieties, working with growers, to recipe development and the ultimate taste of the beer produced. Developing a brand identity for a brewery involves labeling the sensory experiences, which will identify the brand. Brewing beers that are true to the brand is the quality goal.
Quality beer requires “consistently producing a product that has desirable flavor qualities and is free of undesirable flavor profiles,” she said.
Negative attributes of malt flavor include musty, astringent and sour flavors. Some positive flavors associated with malt are vanilla, caramel and nutty. A bread or crusty flavor is good — a moldy flavor is not.
The goal of malt sensory evaluation is to be able to create beer with the desired flavor profile, consistently. Barley variety itself is an important variable in malt flavor. Not only is there a difference in malt flavor from different varieties of barley, but the manner in which the barley is stored, malted and brewed impacts the flavor, too.
Barley Flavor
Malted grains provide beer with some — but by no means all — of its flavor. Trying to sort out which flavor traits come from the grain variety, the growing environment, the malting process or the brewing process can be tricky. Yet the ability to capture a specific flavor profile in beer is the mark of quality.
While barley flavor does not equate with malt flavor, “a lot of malt flavor does depend on barley characteristics,” Dustin Herb, formerly with Oregon State University, said. The research on barley flavor includes experiments to “remove the malting effect, because we know what the flavor is that comes from the malting.”
By brewing enzymatically, a flavor baseline based on the compounds present in the barley itself can be discovered, Herb said. The same barley, grown on one farm, is malted to pale, and beer is brewed either with malt, or with an enzymatic compound. Then researchers can evaluate the persistence of the barley flavor compounds, as well as those from the malting process, throughout the brewing process, and begin to distinguish what flavors are inherent in the grain itself.
Creating a “flavor wheel” of the characteristics of the malted brew, the enzymatic brew, and the barley itself, provides a way to correlate the beer flavor with various aspects of the grain, the malt, and the brewing process. Common flavors identified with barley include: fruity; toffee; malty; woodsy and floral. Some of these are highly correlated with barley variety, Herb said. Finding correlations between the barley flavor and the enzymatically-brewed flavor can help determine what the flavor characteristics of the grain itself, minus the malting effect, contribute to the beer’s flavor.
OSU research also includes screening hundreds of barley varieties for sensory characteristics after malting and nano-brewing. The goal is to “identify more unique flavors within different genetic backgrounds” of barley. Researchers have found more than one quantitative trait locus (QTLs) on the DNA and have been able to associate these QTLs with specific barley flavor.
Malt Flavor
During malting, grains are germinated. Germination causes enzyme production, which break down protein and starch into sugars and amino acids. Starch in the grain endosperm is made available, in a process known as modification. Next, the grains are kilned, or dried. This step, too, has an impact on the enzymatic activity. Both the barley protein level, along with the modification-effect, impact flavor.
Malting variables (temperature, moisture levels and duration) contribute to flavor. The malt flavor, along with that from the water, yeast, hops and other ingredients in the beer add to beer flavor. The brewing process itself affects the ultimate flavor results. Other factors, such as storage throughout the life cycle of the beer’s ingredients, also play a role.
The mechanics of malting definitely do impact beer flavor. No matter what barley variety is malted, variations in taste can be seen, both between maltsters and between varieties. Oregon State University’s Malt Lab is working to combine malt analysis with the barley breeding research. Creating research malts could help to distinguish how a barley variety’s flavor can be best utilized during malting, and its ultimate flavor impacts on beer.
Malt flavor sensory evaluations are difficult. A variety of methods are utilized – making a tea from the malted grains, chewing the whole kernels, making a porridge- but all are either fatiguing, difficult to train people to do, or do not really represent true malt flavor.
“Proper analysis of malt flavor really begins with the method,” Barr said. “We’d eventually like to get to the point when we can start using malt flavor as a predictor of beer flavor. The proper analysis of malt flavor really begins with the method.”
Additional controlled studies, which focus on better understanding the way in which malt flavor is developed, are needed, Barr said. Barr is involved with formulating a more accurate sensory method for assessing malt flavor. Herb has recently left OSU for an internship at Valley Malt, in Massachusetts. He is currently continuing barley and malt flavor research at Valley Malt, in conjunction with the Hartwick College Center for Food and Beverages, in Oneonta, NY, and OSU Malt Lab.
The flavor of beer depends upon many factors from grain to glass. Barley genetics, environment, microbiome and management practices have an impact. Trying to identify and isolate those factors, to control for their ultimate contribution to beer flavor, is complex.

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