What is the difference between phenolic and esters?

Answered by Vince Keith

As a sommelier and brewer, I have spent a significant amount of time exploring the flavors and aromas of different beverages. One of the fundamental distinctions I've come across is the difference between phenolic compounds and esters. While it is important to note that there are exceptions to every rule, I have found that thinking of esters as fruity and desirable, and phenols as spicy and usually unwelcome, has helped me develop a better understanding of these compounds.

Let's start with esters. These compounds are often responsible for the fruity and pleasant aromas found in many beverages. When I think of esters, I imagine the luscious scent of ripe strawberries in a glass of or the enticing aroma of tropical fruits in a well-crafted . Esters can add complexity and depth to a , enhancing its overall appeal. They are formed through the reaction between an and an acid, resulting in the release of . This process, known as esterification, occurs during fermentation in both and beer production.

On the other hand, phenolic compounds tend to impart a spicy, medicinal, or even smoky character to beverages. These compounds are often derived from the phenols naturally present in the raw ingredients used during the or winemaking process. In beer, phenols can be produced by the during fermentation or can be introduced through the use of smoked malts. I recall a particular beer I brewed using smoked malts, which resulted in a distinct phenolic aroma reminiscent of campfire smoke. While this flavor profile may be desirable in certain beer styles, such as Rauchbier, it is generally considered undesirable in most other styles.

In wine, phenols are typically associated with the presence of tannins, which contribute to the wine's structure, color, and bitterness. Tannins are phenolic compounds that are extracted from the grape skins, seeds, and stems during the winemaking process. These compounds can add a drying sensation to the mouthfeel of a wine, similar to the sensation of drinking strong black . While tannins are an essential component of some wines, such as Cabernet Sauvignon, excessive amounts can make a wine overly astringent and unbalanced.

It is important to note that the perception of esters and phenols can vary depending on the individual's sensitivity and personal preferences. What one person may find pleasant and desirable, another may find overpowering or unpleasant. Furthermore, different beverage styles and production methods can greatly influence the presence and impact of these compounds.

To summarize the difference between phenolic and esters, esters are often associated with fruity and desirable aromas, while phenols tend to impart a spicy or medicinal character. However, it is crucial to remember that this is a generalization, and exceptions exist in the vast world of beverages. Understanding the distinction between these compounds can help us appreciate the complexity and diversity of flavors in the beverages we enjoy.