It was not until a street vendor in Boston gave me a friendly vocabulary lesson during my first year of college that I learned it went by other names.

When I asked this man for a pop, he knitted his brow and cast a strange look at me. Out of his mouth came an English that was similar to the one I was used to hearing in the Midwest, and by mentally re-inserting the “r”s, I was able to translate his thick Bostonian accent into something I could grasp. He said: “In Boston, if it’s fizzy and flavored, it’s tonic; soda is club soda; pop is dad, and if you want tonic water, you must ask for tonic water.” (Of course, he pronounced it wadah.)

OK, I’ll accept “tonic.” It may lack the onomatopoeic punch of “pop,” but “tonic”—defined in the American Heritage Dictionary as a “refreshing, invigorating, and restorative agent”—remains truer to the historical origin of soft drinks. Nearly some 2,500 years ago the Greek physician Hippocrates suspected that mineral waters had therapeutic qualities (beneficial to humans through bathing, not by drinking). But in less than 1,000 years, sparkling water had become a beverage: In the 1600s, the Belgian village of Spa, famous for its bathing waters, began bottling the effervescent stuff and shipping it as far away as London.

Sparkling waters were thought to cure everything from arthritis to indigestion. With such healing power, scientists, pharmacists, and physicians set out to analyze the water; in the process, they discovered that the air being released in the tiny bubbles was carbon dioxide. In 1772, Joseph Priestley, the British scientist credited with identifying oxygen, was the first to invent a method for “pushing” carbon dioxide into water. Shortly after, Priestley emigrated to the United States and by the beginning of the nineteenth century, carbonated water was manufactured in North America.

Both artificial and natural mineral waters were soon considered health products, but believing they could improve upon the curative properties, pharmacists began to add natural ingredients—herbs, flowers, roots, even bark—to the fizzy water. And while no miracle cures were discovered, the “flavored” sparkling water was a big hit as a thirst-quenching beverage; particularly popular were ginger ale, root beer, sarsaparilla, lemon, and strawberry.

In 1871, the first U.S. trademark for a carbonated drink was awarded to Lemon’s Superior Sparkling Ginger Ale. Four years later, Philadelphia pharmacist Charles E. Hires tasted a tea made from 16 different roots and berries including sarsaparilla. Hires experimented with the tea recipe and a year later introduced Hires Rootbeer Household Extract at the Philadelphia Centennial Exposition. He renamed his tea on the good advice of a friend who suggested that hard-drinking Pennsylvania coal miners would be more likely to try root beer than herb tea. Curiously, it was at this same time (about 1875) that the term soft drink came into use, referring to any carbonated beverage that was nonalcoholic.

Throughout the remainder of the nineteenth century, pharmacists created new recipes and dispensed them through their drugstores. The year 1886 saw not only the introduction of Dr. Pepper and Moxie, but also what was to become the industry’s giant. Atlanta pharmacist John Styth Pemberton concocted a headache and hangover tonic by mixing a solution of South American coca leaves, an extract of the African kola nut, as well as other ingredients. It would become Coca-Cola.

Certainly cola dramatically boosted the soft-drink industry, but a much less heralded invention, the crown cap, changed the world of beverages—both hard and soft—forever. In 1892, Baltimore machinist William Painter created the cap, along with several other bottling inventions, making carbonated drink containers more portable and stable in shipping. His discoveries took soft drinks out of pharmacy soda fountains and into homes.

As Bostonians continue to remind us, soft drinks are still tonics. With ingredients like sugar, caffeine, ginger, and sarsaparilla, and the effervescent bubbles, the ability of soft drinks to refresh, provide a lift, settle the stomach, or eliminate headaches is now accepted.

It was flavor that became the central issue for many tonics during the twentieth century. The sugar rationing resulting from World War I necessitated the first flavor altering of soft drinks. Over the following decades the change from cane sugar to corn syrup lowered costs but diminished taste. By 1984, the sweetener in Coke and Pepsi was more than 50 percent high-fructose corn syrup and its presence continues to escalate.

A modernized process of brewing and mixing the syrup changed the taste, too. In a 1996 issue of Malt Advocate, Lew Bryson wrote an in-depth article on root beer, “Finally, a Beer the Whole Family Can Love.” In this article, Bryson quotes “Deep Root,” an anonymous industry insider. “Deep Root” explains how root beers are made today: “There are around 20 flavorings in the average root beer. We formulate a flavor for someone based on an old recipe or sometimes mimicking an existing root beer. There’s nothing new out there. Then we ship it out as an emulsion, about 1 gallon of base to 100 cases of root beer. We wouldn’t really like Charles Hires’ original recipe; it was pretty harsh. There’s less bite today.”

I found an even better characterization of the flavor evolution of soft drinks later in the article when Mark Clough of Kemper’s Soda describes the “blandification” of national-market food and drink products. Clough writes, “The blander the product, the more people you can sell it to. As you increase the character, make the flavor more extreme, fewer people like it. But those who like it really like it!”

As with many basic foods that improved in the 1990s as a result of a return to quality ingredients, soft drinks began to experience a kind of flavor renaissance. This was best exemplified by the premium root beers whose makers rejected the widest markets and followed closely behind the craft beer revolution in their microbrewery growth.

Such passion for distinctive root beers—often regional and boutique products—is easily verified: POP the Soda Shop, an online beverage source, lists 24 different root beers, and owner Jeff Guarino says that only 60 percent of what he carries is presented on the Web site. He also refers to the business of gourmet soda pop as “covert, almost anti-retail. I try to have at least five or six sources for each brand since supplies often are erratic and varied.” Many micro-rootbrews are available only in their home region, yet it appears that such scarcity does nothing but fuel the fascination.

For an eye-opening look at root-beer fanaticism, I recommend visiting “Spike’s Root Beer Ratings and Reviews” online (digitalironworks.com/spike/rb). Spike offers in-depth evaluations and ratings of some 29 root beers. For example, Henry Weinhard’s Root Beer, rated an “A,” is only available in 12 western states, and Miller Brewing, who bought Henry Weinhard Brewery, says it has no plans to expand distribution. This made it difficult for me to check up on Spike’s praise of the stuff until POP the Soda Shop sent me two bottles of Henry Weinhard’s. No doubt about it: This is the best root beer I’ve ever tasted—complex, spicy, and with a hint of vanilla and molasses.

While I was waiting for Henry Weinhard’s, I decided to test a nationally distributed root beer named Virgil’s that had won the “Outstanding Beverage” award at the ’94 and ’96 International Fancy Food Shows. Virgil’s, originally brewed in the north of England,was lovingly and artistically recreated by Ed Crowley and his Crowley Beverage Corporation. The microbrew uses all-natural ingredients—unbleached cane sugar, anise, licorice, wintergreen, and molasses. It was rather sweet, but definitely flavorful.

In the process of evaluating Virgil’s, I discovered that soft-drink fanaticism is not confined to root beer. Virgil’s is currently owned and distributed by the Original Beverage Corporation, the makers of Reed’s Ginger Ale, one of the truly great ginger ales (for my money, the greatest). It tastes like ginger and isn’t overly sweet. Chris Reed, the creator of the ginger ale, tells me he started by chopping the ginger by hand and brewing it himself using all natural ingredients. And after he and his wife built the company to $3 million in sales, when it became a top-selling item in natural food stores and was distributed all over the world, they decided to hire another employee.

Chris Reed’s company is now as much about ginger as it is about ginger ale. These days Reed makes candy, cookies, and four different types of ice cream—all with ginger. And he believes that ginger’s popularity will rise, that the root will become known as a disease preventative with healing powers. Anecdotal evidence supports his notion.

Now when I return to Boston, there’s no more sputtered request for “pop...I mean, er...tonic.” With Reed’s Ginger Ale there’s no confusion. It is my true tonic.