While selecting a new alcohol to indulge in, people typically look for a few things to ensure that the spirit is of sound quality. For starters, they make sure that the type of spirit and its brand—whether it is rum, whiskey, or vodka—are per their preference. Next, they are bound to check the volume of alcohol present within the spirit; this will give them an idea about whether a serving of the beverage will calm them or energise them.
Two main indicators usually point out the alcohol content in a bottle. These are “alcohol by volume,” abbreviated as ABV and the “proof.” ABV is a standard measure that signals the quantity of ethanol content within a specific volume of a drink. ABV is a fairly common and accurate way to determine how powerful an alcohol is. It is typically shown as a percentage. Alternatively, proof doesn’t feature on alcohol bottles very frequently; however, its long history can clue people into its various uses.
Before diving into the origin story of proof, let’s understand what exactly the term means.
What Is Proof?
The word “proof” dates back to the 16th century, when it was used to establish the authenticity or dilution levels of a spirit. Currently, the proof is popularly expressed as a numerical value that is double the percentage of ethanol by volume. For example, 80-proof alcohol is composed of 40% ethanol. While the idea is quite simple, potential misunderstandings could arise owing to the different global parameters for gauging alcohol content.
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For instance, in the United States, the proof is exactly double the ethanol percentage by volume. On the other hand, in countries, such as the United Kingdom, France, Canada, and Australia, alcohol proof is the same as the ethanol percentage by volume. This difference could be confusing while examining alcoholic beverages side-by-side globally. Despite this, the concept of proof is popular enough to still be employed by a majority of alcohol manufacturers.
Now, take a look at the fascinating origin story of the term “proof.”
How Was The Term “Proof” Invented?
The idea of alcohol-proofing has origins in mid-16th century Jamaica, when the British Royal Navy colonised the Caribbean nation. One of their many priceless discoveries here was the local sugarcane-based alcohol, which came to be known as rum. The Royal Navy began handing out a daily ration of alcohol to its sailors. However, occasionally the drink would be diluted in the case of limited supplies.
In the absence of scientific methods to determine the potency of alcohol, the sailors took it upon themselves to innovate a technique to measure alcohol content. They would drizzle some grains of gunpowder into the rum, and either set it on fire with a magnifying glass or transfer the paste into a gun. If the concoction caught fire and the gun fired, the alcohol content was judged to be high; if the opposite happened, it was clear that the spirit was diluted. In this way, they had “proof” of how strong or diluted a drink was.
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Another significant reason for performing the proof check was to ensure that any alcohol present onboard the ships would be flammable if a cask broke during battle. Cannonballs and muskets, when paired with wet gunpowder, could be deadly in the midst of combat. Therefore, any cracked spirit needed to remain adequately inflammable to allow the gunpowder to restore its usability.
The method of determining proof underwent an important transformation in 1816 with the development of the Sikes hydrometer. Continue reading to learn how.
The Sikes Hydrometer
This device showcased the exact measurement of alcoholic strength. Owing to this machine, it’s now agreed that 100-degree proof equates to 57% ABV. Before this creation, the Navy obtained spirits, usually rum for the crew and gin for officers, at 100 degrees proof as it was the only strength that could be verified using the gunpowder test; it’s from this test that the idea of Navy Strength Rum was born. Even after the invention of the Sikes hydrometer, the Navy continued acquiring spirits at 57% ABV, honouring this convention and propelling the idea of proof into the future.