Cromaine District Library Shares Ale Together Now: The Sensory Experience Of Beer

Press release from the Cromaine District Library:

April 7, 2021

When we enjoy a beer, typically the first of our five senses to come to mind is taste, but the experience of beer actually involves the stimulation of each of our senses in their own unique way to make our experience with beer what it is. Before you even taste the beer, you experience the sound of beer pouring into a mug or fizzing in a bottle or can; you see the drink in front of you, taking in the sparkling carbonation, the big creamy head, and the color; you experience the texture of the cold can or bottle, or of the glass or wooden mug in your hand; and as you eagerly lift the beer towards your gaping maw you experience aroma, piney, fruity, roasty with coffee or chocolate, bready--and finally, we are graced with the wonderful taste of beer; the sharpness of a sour, the piney bitterness of an IPA, the malty and chocolatey taste of a stout or porter. The texture of the beer also comes into play here. Is your beer a creamy nitro? A thick stout? A crisp, carbonated lager? This month, our friend and beer guide Michelle from River’s Edge Brewing Co. takes us on a sensory journey to explore the importance of appreciating everything that our favorite brews have to offer, including aroma, appearance, and body/mouthfeel.

Our sense of smell is especially important in experiencing the flavor of beer, since smell is one of the strongest senses in the human body. It involves two parts of the olfactory system: sensory receptors and trigeminal nerves. The aroma of a beer is one of the first attributes of a beer’s experience, and also aids in our perception of the beer’s overall “finish." Since our senses of smell and taste are so closely connected, the aroma of a beer is very much a part of the overall flavor profile of a beer, and also helps us detect off-flavors or imperfections in a brew.

Common Aroma Terms:

• Malts – Grain, Roasted, Toasted, Caramel, Smoke, Coffee, Chocolate
• Hops – Citrus, Pine, Floral, Fruit, Grass, Herb
• Yeast – Earth, Spice, Fruit (pear, apple)
• Barrel Aging – Oak, Vanilla, Pecan/Nut

The flavor of a dark, roasty beer like a chocolate stout contrasts greatly with a hoppy IPA.

Off Flavors/Aromas: Just like you can detect the desired notes in a beer’s style--like pine, citrus, coffee, chocolate, and other aromas--you can also detect the undesired aromas. Off flavors or aromas can come from many different aspects of beer production, contamination, and ingredient usage. Some off flavors are classification dependent, which means that they may be red flags for particular beer styles, while also being common and sought after in other beer styles. Here’s a list of some off flavors/aromas you may find on beer and what they might indicate:

• Sour, Tart, Apple – May indicate Acetic Acid Contamination (Lactobacillus and Pediococcus) during the brewing process in some styles, but is a sought after flavor component for Sour Ales, Wild Ales, Berliner Weisses, Kettle Sours, Goses, and Lambics
• Buttery, Buttered Popcorn – Diacetyl (2,3 Butanedione). This flavor indicates a fermentation issue, like interrupted fermentation.
• Cheesy, Funky – Isovaleric Acid. This flavor often comes from the use of old hops.
• Cardboard, Paper – A result of oxidation, this flavor results from prolonged exposure to oxygen. It can also indicate that a beer is old.
• Creamed Corn, Vegetable Musk – DMS (Dimethyl Sulfide). This is a malt issue: it is usually fixed in the boil kettle.
• Hay, Barnyard, Earthy, Funky – This flavor results from exposure to yeast or bacteria contamination, but is a sought after aroma/flavor for Saisons, Belgians, Lambics, and Wild Ales.
• Skunky, Sulfur – This flavor or aroma indicates that a beer is light struck (overexposed to sunlight). This can be prevented by storing beer in cans, dark bottles, or kegs.

Appearance--Color: The first impression we typically have of a beer is based on its color and overall appearance-- and much of a beer’s appearance is dependent upon the grain or malt used in the brewing process and how they are roasted. Malts that have been roasted longer and at a higher temperature are darker in color (and flavor profile) than lighter roasted or dried malts.

The Standard Reference Method (SRM) Color Swatch was developed by the American Society of Brewing Chemists in 1951 to determine the intensity of beer color. It lists numbers 1-40, where smaller numbers indicate lighter beer color and larger numbers indicate darker beer color. Here are some names for common beer colors and their location on the Color Swatch; what number and color is your favorite brew?

Appearance--Head/Foam: The “head” of a beer is the frothy foam at the surface of a glass, produced by Carbon Dioxide bubbles rising to the surface of the glass. Having a head on a beer is essential for the overall experience of a beer – within these bubbles are pockets of aroma and flavor that you may not detect in the liquid alone. A proper beer head is also aesthetically pleasing, and is an indication of a fresh-poured beer. A preferable size for a beer head is style determined, but is usually around 0.5 to 1 inch.

Other components of your beer’s appearance and head also contribute greatly to your drinking experience. For example, have you ever noticed an abundance of bubbles rising from the bottom of your glass? A small etched patch at the base of a glass called a nucleation point allows bubbles to cling to and accumulate within that location until they are buoyant enough to rise to the surface of the beer, replenishing the head/foam. Another interesting component of a beer’s appearance is Lacing, which occurs when bands of foam cling to the side of a beer glass as the beer is consumed. The ability for beer to lace along the side of a glass is indicative of very clean, well-rinsed glassware. Nitrogen also has an important role in beer foam. Nitro beers are infused with Nitrogen instead of carbon dioxide after fermentation. Nitrogen gas is not as soluble as carbon dioxide is, and as a result it produces very small bubbles in comparison to carbon dioxide. This is what gives Nitro beers a very creamy, smooth, and stable beer head.

Nitro beers (right) have a much fluffier and richer head than a carbonated beer (left).

Mouthfeel and Body:

Carbonation:

Body: A beer’s body is determined by the general feel of denseness and viscosity. A light-bodied beer will come across as a crisp, clean drink, whereas a medium or full-bodied beer will come across as thicker.

Aftertaste:

Beer Styles and their Mouthfeel/Body

• Light-bodied beers – crisp, clean, effervescent
• Medium-bodied beers – smooth, creamy
• Full-bodied beers – smooth, creamy, thick
• Barrel aged beers – warming, hot, alcoholic, tingly

ABV and IBU: The alcohol by volume (ABV) and International Bitterness Unit (IBU) are ways to describe a brew by how much alcohol was produced during fermentation and how bitter the flavor and aroma may be.

Alcohol by Volume (ABV):

A beer’s alcohol content is determined by the following formula:

ABV = (OG – FG)

By subtracting the Original Gravity (OG), the density of the wort before fermentation, by the Final Gravity (FG), the density of the wort after fermentation, a brewer can determine how much of the fermentable sugars in a brew were converted into ethanol.

Brewers use a Hydrometer to determine their Original Gravity and their Final Gravity, indicating the Alcohol By Volume of the beer.

International Bitterness Unit (IBU):

Next time you’re enjoying a beer--be it a classic favorite or a new, experimental brew--keep all of your senses at the forefront of your mind. By paying special attention to the aromas, appearance, and mouthfeel of the beer, you may have a more well-rounded, complex, and interesting experience than expected. Cheers!

• Play with some of these terms as you try a new beer!
• Often the first attribute detected by the mouth is the level of carbonation; essentially, how bubbly is it? A beer that feels flat on the palate likely has a low level of carbonation as opposed to a beer that makes the tongue feel tingly. A beer with large bubbles of CO2 may feel crisp while tiny bubbles will give off a creamy, smooth texture.
• The finish of a beer rounds out its overall experience. You may even detect new flavors or aromas from the aftertaste of the beer that may not have been detected earlier on.
• The IBU is a standardized measurement of how bitter a beer is upon one’s palate. It specifically measures the parts per million (ppm) of isohumulone particles [an alpha acid chemical compound], which is provided by the addition of hops into a brew. Keep in mind that “hoppy” does not always mean “bitter” in describing a beer!
• The ABV is a standardized measurement that determines the amount of alcohol, specifically ethanol, within a given volume of liquid. That is, the number of milliliters (mL) of ethanol within 100 mL of liquid at room temperature. This measurement is usually represented as a percentage. The ABV of most beer styles fit within the range of 3.0-15.0%. The alcohol content of beer is determined by the amount of fermentable sugars available to the yeast during fermentation. Ethanol is a byproduct of yeast activity (as it consumes sugars); thus the more fermentable sugars are extracted from the malt and become part of the brew liquor, the higher the achievable alcohol content.
• In addition to a beer’s aroma and flavor, mouthfeel is essential to the overall experience. A beer’s mouthfeel is its overall texture on the palate. There are three factors to keep in mind when assessing a beer’s mouthfeel: carbonation, fullness/body, and aftertaste.

This press release was produced by the Cromaine District Library. The views expressed are the author's own.