While many wines are designed to be cellared for years and even decades, that’s not the case with spirits. If they’re matured, all that aging happens before they’re packaged for sale. 

But antique bottles of whiskey—and tequila, and rum, and more—hold special appeal for collectors and enthusiasts thirsty for a taste of the past. Once upon a time, such “dusties” were fairly easy to find gathering, well, dust on the back shelves of liquor stores, relics of the "glut era" of bourbon or other trends that didn't pan out. Nowadays, those shelves are picked over, and some are going to far greater lengths to acquire these historic sips. And with good reason. Bottles of Willett Family Estate from just 20 years ago can sell today for thousands of dollars; some, like the legendary Red Hook Rye (original price $75), for tens of thousands.

A new book called Dusty Booze: In Search of Vintage Spirits delves deep into the world of dusties, following professional buyers, like bartenders curating specialty menus, and deep-pocketed collectors around the United States, and the world, in search of spirits that were made and bottled before they were born. Author Aaron Goldfarb ably separates legend from fact and intersperses lively and entertaining narratives with comprehensive information about alcohol history and the dusties that are most in demand today.

He also provides a concise how-to for figuring out just when a particular bottle was produced—since, unlike wine, spirits almost never carry a vintage date, and their logos and labels may go decades without modification. Keep this guide handy for the next time you stumble across a stash of old bottles in a relative’s basement.

On December 23, 1975, America went metric. President Gerald Ford thought getting our measurements on track with the rest of the world was critical in keeping us a global power. Earlier in the year, Congress had passed the Metric Conversion Act, making metric the preferred measurement system of the United States. A U.S. Metric Board was even created to oversee the conversion. 

I can easily imagine all the dumb protests today—all the Ted Cruz tweets smugly showing him holding a ruler with inches—if an unpopular president took away our beloved gallons and miles. Then again, many people weren’t thrilled with it back then either. There were anti-metric parties held across the country. Eventually Congressman Chuck Grassley—who, as I write this, is improbably still in office, now in the Senate, at nearly ninety years old!—was able to kill these federal regulations, and by the time of Reagan, metric was kiboshed.

Except in the beverage industry.

By 1979, American brands had completely switched over to eight standard sizes: 50 milliliter (mL), 100 mL, 200 mL, 375 mL, 500 mL, 750 mL, 1 liter (L), and 1.75 L. With just a few additions, those metric sizes still prevail today.

Meaning: If you find a bottle measured in imperial units, you know you’ve scored a dusty from back when ’murica didn’t let the French dictate how we boozed. In fact, in the 1960s and 1970s there were dozens of different-sized bottles. Pints and quarts and even gallons.

Pints were often offered in flat packaging, like a hip flask. And as early as the 1950s, distilleries like Jim Beam, National Distillers, and Stitzel-Weller produced remarkable gallon-sized bottles—that’s 128 ounces—so large and unwieldy many came packaged with a wooden “swing,” allowing one to pour a bottle without actually having to lift it.

Ever wonder why a standard 750 mL bottle is called “a fifth”? Because before the metric system, it was indeed labeled one-fifth of a gallon (or sometimes four-fifths of a quart).

If some booze has that oh-so-scary government warning on it—“According to the Surgeon General . . .”—it was bottled after 1989. But if it lists just the proof (and no ABV percentage), it’s probably older than 1990.

Another key signifier of vintage is the tax stamp—in essence, a cheap strip of paper tape across the bottle cap. From 1897’s Bottled-in- Bond Act until 1985, the government mandated that distilleries include these to assure both customers and, more importantly, tax inspectors that no one had opened the bottle and futzed with its contents in this era before tamper-proofing.* Thankfully, most tax stamps will list both the year the liquid was distilled and the year it was bottled, making dating easier. (Look for a green tax stamp for bonded bourbons and red for all others.)

Of course, sometimes tax stamps can be hard to read; sometimes they may lack dating information; other times the vintage spirit may be from a category that didn’t have as strict regulations. In that case, things can get tricky, and you might have to pull out the magnifying glass.

Occasionally, the last two digits of a bottle’s bottling year are embossed in the bottom glass. By scrutinizing a vintage bottle’s barcode, specifically the first five digits, you can often tell who bottled a given whiskey, something critical with bourbon brands so often changing hands while labels so often remain mostly looking the same.

For instance, Jim Beam, the current distillers of Old Grand-Dad, will have a UPC prefix of 80686 on all its whiskeys. If the bottle has 86259 on it? That would mean you’ve lucked into some vastly better National Distillers supply from before 1987.

You can likewise look for the DSP number, which is almost always on bottles of bonded whiskey. Standing for “distilled spirits plant,” the code tells you where a particular bottle was distilled. Stitzel-Weller, for instance, was DSP-KY-16, meaning if you discover a bottle with that code on it, you’re in for a treat.

And when all else fails, when you can’t figure out who distilled your bottle or what year it’s from, many people just message bourbon historian Mike Veach at his website (bourbonveach.com) or DM Eric Witz (@aphonik) on Instagram.

Aaron Goldfarb is a novelist, author, and journalist writing about the spirits industry and drinking culture. He was named 2020’s Best Cocktail & Spirits Writer at Tales of the Cocktail’s Spirited Awards and won 2022’s International Association of Culinary Professionals award for Narrative Beverage Writer.

Excerpt reprinted with permission from Dusty Booze: In Search of Vintage Spirits by Aaron Goldfarb © 2024. Published by Abrams Books.