Why One Spirit Can Have Many Different ABVs

Why does a bottle of whiskey or rum or even Campari have a different ABV in America than it does in, say, Australia or the UK? Bryce T. Bauer on the case of the varying alcohol percentages, how we got to the proofs we use today and why producers are deviating from them more often.

Spirits Proof

Recently, I found myself sitting in the tasting lab at the Mount Gay distillery tucked away in the canefields of St. Lucy, Barbados, getting schooled in rum-making by master blender Allen Smith. In a conversation that delved into many obscure topics, it was a far more routine discussion that finally stumped him.

Why were all of the bottles of Mount Gay Eclipse I was seeing on store shelves labeled as being 43 percent alcohol by volume, while I was certain the bottles I had seen in America were labeled 40 percent? Smith had just added yet another wrinkle: In Australia, Eclipse is released at 37.5 percent.

“It’s diluted to whatever they say we are supposed to dilute to,” he said.

This is not a phenomenon relegated to just rum. Spirits across most categories vary by region and have even changed over time. Campari, for example, is sold in most parts of the world at 25 percent ABV. In the United States, however, it’s 24 percent, and in Brazil and elsewhere in South America it’s popped up to 28.5 percent. Or take Bombay Sapphire: In the U.S., drinkers get it at 47 percent, while in the United Kingdom, the Caribbean and New Zealand, it’s 40 percent, and in South Africa, it’s bottled at 43 percent.

Other spirits have simply dropped over the years: Jack Daniels was once bottled at 45 percent alcohol, before dropping to 43 percent, and then, again, down to 40 in the United States. And in the United Kingdom, Gordon’s gin followed a similar trajectory: Once bottled at 40 percent, today it’s sold at 37.5 percent, says Edgar Harden, a London-based vintage spirits dealer who tracks data across time and geography for the bottles he sells on his website, Old Spirits Company. Overall, he says, spirits have generally become weaker over the last few decades. And as proof decreases, so does flavor.

As it pertains to whiskey, the difference in the flavor of spirits bottled at today’s standard—40 percent ABV, or 80 proof—and the standard proof at the beginning of the century—100 proof—is significant.

“It certainly seems like a lot more than 20 [proof],” says John Little, the master distiller at Smooth Ambler, who frequently bottles liquors closer to 100 proof. “A lot of times I drink spirits that I know are really, really good and wonder, hey, where did all the flavor go?”

But, why? I wanted to know. Why did the proof of spirits vary so much around the world and through the ages? And why did America dictate as part of its “Standards of Identity for Distilled Spirits” that whiskey, rum, gin, tequila, brandy and vodka be bottled at 80 proof when other places set their minimum proof at a different level?

For the most part, Smith was essentially right. In many countries, the ubiquitous proof is the lowest regulation a particular place will allow. (Or in the case of Barbados, tradition: Despite the law actually allowing producers to go as low as 40 percent, rums have almost always been bottled at 43 percent.) But that doesn’t tell us how we got to 80 proof.

When I put the question to some booze historians, to the Distilled Spirits Council of the United States and to the Alcohol and Tobacco Tax and Trade Bureau, the agency that’s responsible for administering those standards, none of them could tell me exactly why 80 was decided on as the minimum—and then, ultimately, the standard.

It seems that America arrived at it in the wake of the passage of the 1906 Pure Food and Drug Act, which gave the federal government the power to mandate that what a product said on the label actually matched what was inside. (And it takes only a cursory glance at the horrors of what was actually in products of the era, including booze, to realize how far those two things were from each other).

Following that legislation, bureaucrats spent a couple of years trying to figure out just what whiskey was. Among the standards they settled on was that it had to be bottled at 40 percent ABV, a provision that seems to have then been applied to other distilled spirits in America as well. But 80 proof was just the minimum—the lowest a bottle of whiskey could be sold and still be deemed worthy of being called whiskey.

Such a low proof, however, was not the vanguard. South Dakota chemistry professor James Henry Shepard, who helped set the law, wrote in his book The Constants of Whisky that 80 proof had traditionally been the hallmark of a whiskey that was “wholly factitious.” At the time, what connoisseurs were typically pouring was bottled at 100 proof.

To get from 80 proof being the minimum a whiskey could possibly be bottled at to being the ubiquitous proof took a number of different shifts in drinking culture. Newspaper reports suggest the 100 proof standard held through the first decades after Prohibition. But by the middle of the century, the Times noted that usual standard had fallen significantly, citing industry sources that estimated only about 15 percent of whiskey sold was still bottled at 100 proof, while 72 percent fell somewhere between 86 and 90 proof, and the remaining 13 percent was 80 proof.

The reason for that drop, says Noah Rothbaum, the author of The Art of American Whiskey and the food and drink editor at The Daily Beast, was likely related to two factors: the need to stretch whiskey stocks during wartime and the palates of returning American GIs who’d become accustomed to drinking lower-proof Scotch.

It would take another invasion of a different sort, however, to push whiskey down to its bare minimum: vodka, a spirit Harden has found to have been, unlike whiskey, unusually stable at 80 proof over the decades. As vodka stole drinkers away from whiskey in the 1970s, American whiskey makers decided to win them back by producing a lighter product. To do so, many cut to 80.

But producers also had another incentive to lower the alcohol content of a spirit—a motivation that has arguably had a greater influence on why spirits today are often weaker than spirits of 50 and 100 years ago: money.

Simply put, more dilute spirits are cheaper to produce. Not only does doing so allow distillers to get more bottles out of every drop of alcohol they produce (a drop in proof from 100 to 80 can create about a half-dozen extra cases per whiskey barrel for a distiller), but each of those bottles carries a lower tax burden, which, in the U.S., makes the federal taxes on an 80 proof bottle 53 cents lower than on a 100 proof one. In a competitive market, those extra two quarters, once magnified by distributor and retail markups and the addition of state taxes, can have a significant impact on the bottle’s apparent value.

Despite that disadvantage, many craft distillers have moved away from the 80 proof standard and are releasing spirits at a bevy of different, higher alcohol levels. As they do, they are finding that far from there being one proof that works for all products across all classes of spirits, each individual bottle often has a proof at which the distiller thinks it’s best. Moreover, it’s one that often varies based on how that spirit is likely to be consumed, whether via cocktails or on its own.

One of those distillers is Lance Winters, the master distiller at St. George Spirits. For him, the proper number is often arrived at only after tasting the spirit at numerous different alcohol levels.

For example, for their Baller whiskey (“a California spin on the Japanese take on Scotch whisky”), that process resulted in a bottling proof of 94, a point at which they felt it could cut through a bowl of ramen.

But proof isn’t determined by taste alone. Chemistry also has a say. Spirits with higher congener levels—such as aged spirits that haven’t been chill filtered, or anisette liquors—require more alcohol to keep those chemicals from falling out of suspension and becoming cloudy, as absinthe does every time you add a few drops of water into it. Moreover, for gins, where aroma is important, diluting the spirit too much increases the surface tension and prevents the aromatic chemicals from escaping and reaching the nose, says Winters.

While proof used to be a decision left largely to the producer, increasingly it’s becoming a topic that well-educated bartenders and spirits professionals are also commenting on, says Smooth Ambler master distiller John Little. When his company originally released their Greenbrier Gin, they did so at 80 proof. But feedback from consumers was that the gin got lost in cocktails. “It was the single biggest complaint we had on our gin, [and] the only thing we heard on a consistent basis,” he said of the proof. So they upped it to 90, in turn strengthening the flavor.

Whatever the future trends for proof, what seems clear is that the spirits aimed at drinkers who care more about what’s in a bottle than its price are likely the ones that will continue to deviate from the standard proofs. Which may be why, when I circled back to Mount Gay to confirm I’d scribbled down all those proofs correctly, they not only confirmed I had, but also added a gentle reminder: Unlike Eclipse, their higher-end varieties are sold at 43 percent worldwide.