Polyphenols, those magical compounds that add flavor, aroma, and color to beer, are derived from two main sources: hops and malt. Hops contribute around 30% of the polyphenols found in beer, while malt accounts for 70% to 80% [36].
Let's start with hops, those beautiful green cones that give beer its bitterness, aroma, and unique character. Hops are rich in polyphenols, particularly flavonoids such as catechins and proanthocyanidins. These compounds not only add bitterness to balance the sweetness of malt but also provide antioxidant properties and contribute to the beer's overall flavor profile.
The specific types of hops used in brewing greatly influence the polyphenol content of the beer. Different hop varieties have varying levels of polyphenols, which can result in distinct flavors and aromas. For example, noble hops like Saaz or Hallertauer tend to have lower polyphenol content, resulting in a more delicate and floral character, while American hop varieties like Cascade or Citra are known for their higher polyphenol content, which imparts bold citrus and tropical fruit flavors.
Moving on to malt, the backbone of beer, it also plays a significant role in contributing polyphenols. Malting is the process of germinating and drying barley to activate enzymes that convert starches into fermentable sugars. During this process, polyphenols are formed and extracted from the malt. These polyphenols include flavonoids such as flavanols and anthocyanins, which can add complexity and color to the beer.
The degree of malt roasting or kilning also affects the polyphenol content. Lightly roasted malts, such as Pilsner malt, have lower polyphenol levels, resulting in a clean and crisp beer. On the other hand, heavily roasted malts, like chocolate or roasted barley, contain higher levels of polyphenols, contributing to the rich flavors and darker hues found in stouts and porters.
It's worth noting that the brewing process itself can influence the polyphenol content in beer. Factors such as mashing temperature, pH levels, and fermentation conditions can all impact the extraction and transformation of polyphenols. Brewers have the power to manipulate these variables to create a wide range of beer styles with varying levels of polyphenols.
In my personal experience as both a sommelier and brewer, I have noticed the importance of understanding the source and characteristics of polyphenols in beer. By selecting the right combination of hops and malts, brewers can create beers with unique flavor profiles and visual appeal. It's fascinating to see how these compounds interact and evolve during the brewing process, ultimately shaping the final product that we enjoy.
To summarize, the polyphenols in beer primarily come from two sources: hops and malt. Hops contribute around 30% of the polyphenols, while malt accounts for 70% to 80%. The specific hop varieties and malt roasting levels determine the types and levels of polyphenols in beer. Brewers can manipulate these factors to create a wide range of beer styles with varying polyphenol content. Cheers to the complex and flavorful world of polyphenols in beer!