We can look for certain things with good faith on our favorite bottles of spirits. Front and center, bold, sometimes brash, brand names hug the curvature of the glass. Details of manufacture boast of select ingredients and refined processes. The bottle itself curves and entices with blown details. Then, on a corner in small print a number followed by “ABV”.
The ABV (alcohol by volume) is a legal requirement for all alcoholic beverage labels. Consumers have a right to know what they’re getting themselves into when they purchase a bottle. It is optional, but permissible, to include a proof measurement as well. In the United States, proof is exactly double alcohol by volume. But why do we use a redundant measurement such as proof? More importantly, how do we measure alcohol by volume in the first place?
We can measure the strength of our booze using either alcohol by volume or proof. Both of these measurements describe how much ethanol is in a drink as a percentage of the total liquid volume. Alcohol by volume spans a normal 100 percentage points with typical beers measuring from 4-7%, wines from 11-13%, and liqueurs and spirits from 28-50%. Proof is simply double this number and, in that specific proportionality, is used only in the United States.
The term proof has British origins dating back to the 1500s when alcohol was tested for tax purposes. Strong spirits were levied with an excise tax. To decide which spirits were taxed as strong, the tax man performed a sort of experiment. Booze was poured on a bullet and if it still ignited, then that was proof of the strength of the alcohol. This threshold would mean your spirit was somewhere around 50% alcohol by volume. This established a specific ratio that the term proof represented in England, but it has been used to mean double the alcohol by volume in America since the 1800s.
We might know how strong our drinks are when we buy them at the liquor store, but how do we measure the strength of alcoholic beverages at home? If you make your own booze, there are several methods that can be used to estimate and accurately measure just how much alcohol there is in a liquid.
First of all, if you know how much sugar is being added to a fermentation, you can calculate how much alcohol could theoretically be produced by yeast. If yeast have not died off due to the strength of the alcohol, all sugar should be converted to alcohol. Generally, 1 pound of sugar in 1 gallon of water can yield 6% alcohol by volume. Beer brewers are familiar with a version of this method as they measure the density of their brews before and after fermentation and deduce from these measurements how much sugar has been metabolized into alcohol.
An alcometer is exactly what it sounds like—an alcohol meter. It is a kind of hydrometer specifically gauged for ethanol. It looks just like a thermometer and measures alcohol using buoyancy. The alcometer is suspended in alcohol and floats according to the concentration of alcohol in the liquid. Alcohol is less dense than water, so as the percent alcohol increases, the liquids density decreases. As it decreases, the alcometer sinks more and more. The tool is calibrated in such a way that the meniscus of the booze will show the proof or ABV of the liquor. This method of measuring is really only suitable for unadulterated, strong spirits. The presence of sugar in the liquid will distort the measurement. Temperature, too, will influence how the tool measures density.
When testing strong spirits, you can simply shake a glass jar and watch the bubbles. This is the manner of proofing most popular for those without scientific instruments. It can be casually referred to as the shake test. When you shake your booze, you are looking for two things: the size of bubbles, and the duration of bubbles. Big bubbles that are quick to disappear are a sign of high-proof spirits. Lots of small bubbles that stick around indicate that your booze is relatively weak. Because alcohol is less dense, it allows for air to consolidate into larger bubbles and releases them quickly. The higher density of water forces air into smaller pockets but also allows them to remain in the liquid. This method requires practice. There is no sure-fire way to shake and say this is 57% ABV, but a practiced distiller can get a knack for naming proof within a couple degrees of the actual ABV.
It is, after all, important to measure how much alcohol is in a drink. Whether you’re drinking a 4% mass-market beer or a 10% imperial IPA makes a big difference when you might be driving home afterwards. It is worthwhile to know not only what the percentage means on the side of a bottle but also how it was measured in the first place. Remember, proof originally came from strong spirits—so the most rudimentary test is to hold a match to your booze. If it ignites, that’s proof enough you have some strong stuff.
A review of cook books and culinary histories in Savannah and Charleston reveals a variety of herbal teas, complex punches, and foraged fermentable. While sweet tea appears in these texts, it seems that the drinks of the Low Country past were far more colorful.
There is another moonshine in the United States of America. It hides on the island of Puerto Rico, where distillers make pitorro out of sugar cane and fruits. Port Morris Distillery in the Bronx brings this spirit to New York and keeps the tradition alive.
Cafe’s close well before dessert time, but that doesn’t stop them from serving ice cream. It stays rooted in the morning tradition with a shot of espresso. This is the affogato. A classic Italian mix of espresso and dairy. It is a treat of many contrasts.
Yet for something so uniquely American, the native succulent has been given a very Greek name. Agave was the mother of the king of Thebes who famously killed her own son, King Pentheus. In her defense, she only killed her son because she was blinded by a divine madness brought upon by the worship of the god of wine, Dionysos. That means your tequila is made from a plant named after a woman who got a little too crazy off the god of wine. So how did this Greek name end up on a Mexican bottle?
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