ABV: alcohol by volume, a number that appears on your beer, wine, cider, spirits or even kombucha bottles. You know the scale, and generally how different products taste and feel at various levels. But what are we really talking about, scientifically speaking, and how do we interpret the gradation of alcohol in styles and products?
First of all, there are multiple ways to indicate total alcohol in a beverage. In addition to ABV, there is also ABW, or alcohol by weight. It turns out alcohol is less dense than water, and so we can determine the overall makeup of a beverage. ABV is similar, just expressed as a percent of the volume instead of weight. Most labels in this country use ABV to indicate alcoholic content, but some state and federal legal restrictions do use ABW, like Utah’s 3.2% (by weight) limit on beers. This of course equals 4% ABV, which is considered Utah’s division between beer and spirit or “hard liquor.” States vary on where, how and when alcoholic beverages over certain percentage can be sold, but the measurement and labeling is obviously important to all consumers. You should always know what you’re getting into, or what you’re serving someone.
Most smaller brewers and homebrewers use a couple of devices to measure alcohol in beer (and wine and cider). One simple device is a hydrometer, which is a weighted glass object shaped somewhat like a thermometer that can determine the specific gravity (amount of dissolved solids, in this case, sugars) in a liquid by means of physical displacement. When you measure the initial, unfermented product and compare it again to the finished, fermented product, you can calculate how much of the sugar was turned into alcohol. Sounds complicated, but it’s actually very simple. The other device frequently used is a refractometer, which can determine the specific gravity by using refraction of light instead. Larger highly commercial-scaled brewhouses may use a different array of more complex and precise lab tests and other devices (for instance, those that use Near Infrared Technology) to determine alcohol content, and some smaller companies may send their product to labs to have those tests done periodically.
Many styles of beer have terminology that seems to indicate alcohol levels like “session,” “imperial,” and “mild,” but for the consumer they can sometimes be more confusing than helpful. In the US, we have no protected titles for beer–other than trademarked terms and product names, of course. In Europe, there are many more protected titles for locally-made products, from wine to sausage to cheese and yes, sometimes even beer. For example, to label a kölsch as a kölsch in Germany it must be: brewed within the Köln metropolitan area, pale in color, filtered, hop-accented, brewed with a top-fermenting yeast, and in a certain gravity range. Our American naming conventions have a lot of flexibility, which is easy and far less restrictive. The other side of that, however, is that it can misguide or surprise consumers.
Taste and Appreciation
Lastly, alcohol does have a taste, though in beer it’s mostly just one small element in a mix of many other flavors and isn’t usually the most prominent. Higher-alcohol beers, especially when young, can bring a harsh, hot, bitter flavor that usually recedes over time with proper aging and controlled oxidation, though not everyone is averse to that harshness. Alcohol also changes how you perceive a product’s other tastes…general enthusiasm about a beverage also can vary depending on quantity consumed! A good bartender would end this discussion by telling you to know what you’re drinking and consume with moderation, not just for health and sanity but also for the best experience. You don’t always want a complex drinking experience, but I strongly believe the products and all those who had a part in getting them onto your table/bartop/airplane tray/lawnchair deserve a little moment of respect. Cheers…!
Categories: What's That Number?