“I could walk out on the sidewalk outside the bar and do a maceration of the weeds in the cracks and call it a fernet,” Billy Sunday partner Alex Bachman is quoted as saying in the new book Amaro: The Spirited World of Bittersweet, Herbal Liqueurs (Ten Speed Press). Author Brad Thomas Parsons, who also wrote Bitters: A Spirited History of a Classic Cure-All, aims to demystify amaro—a difficult task since there’s no legal definition of amaro and, while it’s most often associated with Italy, it can be made anywhere. Parsons explains in the book, “Generally speaking, amaro refers to the collective class of Italian-made aromatic, herbal, bittersweet liqueurs traditionally served as a digestif after a meal. Amari are created by macerating and/or distilling bitter barks, herbs, seeds, spices, citrus peels, flowers, and other botanicals in a neutral spirit or wine that is then sweetened with a sugar syrup.”

Then there’s fernet, a subcategory of amaro, which—as Bachman notes—is equally unregulated, though Parsons writes that the style is generally a little higher in alcohol and more aggressively bitter than other amari. After introducing the Italian amari currently available in the U.S., Parsons moves on to the ones made elsewhere; while much of Europe has been making amaro for centuries, in the U.S. it’s taken off just recently along with the craft distilling boom, and Parsons lists more than 20 American-made amari (including local favorite Jeppson’s Malort, which isn’t usually called an amaro but fits the broad definition). Chicago alone has several: CH Distillery makes both an amaro and a fernet, while Letherbee makes fernet and besk—the latter created in collaboration with the Violet Hour and originally called malort, then relabeled after a trademark dispute with Jeppson’s.

Alex Bachman of Billy Sunday

Bachman is quoted extensively in the book, and for good reason: Billy Sunday, according to Parsons, has the largest amaro collection in the country at more than 600 bottles, including vintage ones that date back to the early 20th century. And there’s a lot more out there, Bachman says. “I know it looks like we have everything under the sun, but Billy Sunday’s back bar represents a very small fraction of what’s been produced in the last 150 years.”

Earlier this year Bachman launched a brokerage called Sole Agent to import rare and vintage spirits, which started with amaro and quickly expanded to whiskey, rum, and other spirits. He’s constantly coming across amari that he’s never heard of before, many of them long since discontinued. His most recent find was china de cacao, which Bachman says was meant for children, “like the world’s first Robitussin.” It’s made with alcohol, cinchona bark (the main ingredient in quinine, long used to treat malaria and other illnesses), cacao nibs, and lots of sugar.

What drew Bachman to amaro, though, wasn’t the idea of giving it to children as medicine, but his background in wine. “What I loved in wine was the idea of terroir, that the taste and smell of where these things are from makes these wines so distinctive,” Bachman says. “Whiskey has a sense of place, but the basic science of distillation strips out a lot of the congers and flavor profiles you’ll find in wine, where it’s just fermented, not distilled. Amaro, to me, had the best of both worlds.”

The Victorian at Billy Sunday is made with Amaro Sibilia

He’s especially fascinated by the lack of regulation in amaro production. “These guys can do whatever they want to do. If they want to make amaro out of bubble gum and a tire, it’s not going to taste good, but they can do it,” Bachman says. “I think it’s awesome. You can see the apex of people’s creative potential in these products.”

Parsons will be in Chicago this weekend for three local events, two at Billy Sunday and one at Milk Room.

Sun 11/13, 3-5 PM, Billy Sunday, 3134 W. Logan, 773-661-2485, $115: The event will include a copy of the book, cocktails, and tastings of vintage amari pictured on the cover of the book, including Zucca Rabarbaro, Averna, and Fernet Branca.

Sun 11/13, 7:30-9:30 PM, Milk Room, 12 S. Michigan, tocktix.com, $250: Paul McGee and Brad Parsons will lead a guided tasting of four amari from the 1960s and ’70s and serve cocktails made with 1950s Campari and Cynar.

Mon 11/14, 7-10 PM, Billy Sunday, no cover charge: Parsons will sign books and talk amaro.