Everyone in the cocktail business knows what a Lewis bag is. The thick, heavy-duty canvas bag is used to crush ice into fine shards, using a large wooden mallet, and is commonly hauled out any time a craft cocktail bar needs to make a proper Mint Julep.

What nobody in the cocktail business knows is anything about the Lewis bag: when it was invented; how long it has been in use; how it became popular. Who Lewis even was — if it was a person at all — is a mystery.

The early to mid-aughts of the cocktail revival were a period that could be called the Gullible Years. Bartenders and cocktail journalists, drunk on the romance of barroom history and hungry for any intelligence they could find about how cocktails were made before Prohibition, were prone to accept any story about the good old days. Antoine Peychaud, of bitters fame, invented the cocktail? Cool. The Sazerac was originally made with Cognac? Awesome. The Old Fashioned was created at the Pendennis Club in Louisville? Amazing. (None of these tales, once widely held to be gospel, are true.)

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Regarding the Lewis bag, the received wisdom, which began to gel in the mid-aughts and remains firm today, is that it is a tool that dates back to the bartending methods of the 19th century. The trouble with this belief is it is based on almost nothing.

“I, too, assumed that the Lewis bag dated back to the days when block ice was delivered to the bar and bartenders had to break it down into different grades of ice for specific drink preparations,” says Tony Abou-Ganim, an OG cocktail bartender who was one of the leading forces in the craft cocktail revival in San Francisco in the 1990s.

Mojitos were big in San Francisco back then, and to make a good one, you needed crushed ice. Abou-Ganim didn’t have access to such ice, so he smashed up ice cubes using a linen napkin and a meat tenderizer. Then, somewhere around 1998-99, an ad caught his eye: “Authentic 1940s Lewis Ice Bag” complete with mallet. He bought one.

The Lewis bag is manufactured — then and now — by a barware company called Franmara, based in Salinas, Calif., and founded in 1970. The product Abou-Ganim received came in a tube that contained an off-white canvas bag, a wooden club, and a recipe pamphlet.

“Congratulations on your purchase of The Lewis,” the pamphlet read. (I recently bought a copy, dated 2001, on eBay.) “With it, you’ve just acquired the secret to one of life’s most elusive pleasures—the perfect cocktail. After just one use you’ll understand why the classic ice bag and club were considered essential by master bartenders in the days when the cocktail was king.” Thereafter follows 16 cocktail recipes requiring hand-crushed ice, not one of which, curiously, is the Mint Julep.

As to the product’s name, the book said, “The Lewis is named after the good doctor of the same name who, with his ice bag and club, has, for many years, been making what are undoubtedly the world’s best Martinis.” Yeah, right. (Franmara could not be reached for an interview for this article, despite several attempts.)

What small amount of press the Lewis Bag netted swallowed the Franmara story without question. “In the golden era of the cocktail,” wrote The Gazette of Montreal in 1997, “master bartenders had a secret for making the perfect Martini: only freshly-cracked ice can impart the ideal amount of water to alcohol, while rapidly reducing its temperature to a point far below whole ice cubes.” A 2000 article in the Richmond Times-Dispatch called the Lewis Bag “John D. Rockefeller’s Favorite Bar Tool.” (Rockefeller was a known teetotaler.)

The concept of crushing ice for drinks in the 1940s, the Lewis bag’s supposed decade of origin, was not a new idea. David A. Embury, in his influential 1948 book “The Fine Art of Mixing Drinks,” recommended wrapping ice in canvas and whacking it with a mallet. Cocktail expert and author Robert Hess, in his research, found 1940s ads for a similar canvas bag-mallet set geared not toward bars, but households. It was called Krax Ice and made by Baker-Lockwood in Kansas City, Mo. But all evidence I have found — and there isn’t much — indicates that the Lewis bag, under that name, did not exist until the late 1990s. Hess, who became aware of Franmara’s Lewis bag around that time, says “I wouldn’t be surprised if they were the first to ‘re-introduce’ this product, give it the ‘Lewis’ name for one reason or another, and then the others just picked it up from there. I have not been able to yet find any reference to a ‘Lewis Bag’ which predates the Franmara product.”

And yet, by 2010, the Lewis bag was the name accepted by the bar world as a must-have tool in the craft cocktail bartenders’ arsenal. So how did this happen?

No one’s quite sure, but it happened quickly. In the early days of the cocktail revival (late ‘90s, early ‘00s), nobody was using Lewis bags or anything like them. Chris McMillian, the New Orleans bartender who is now famous for his hand-wrought Mint Juleps, was at the Ritz-Carlton in the early aughts. When someone ordered a Mint Julep, he got creative tool-wise.

“I used shoe bags at the Ritz,” McMillian says. “Brand-new, Ritz-Carlton shoe bags. They worked perfectly. I used them for years until my supply ran out.” Charles Joly, working at The Drawing Room in Chicago, used lint-free towels and a mallet to break up ice. And at Blackbird, the short-lived Manhattan cocktail bar opened by Dale DeGroff in 1999, cubes were crushed by hand. “Lacking access to any sort of advanced bar tool websites, Dale taught us to individually crack the cubes with our wooden muddlers,” recalls Audrey Saunders, who worked with DeGroff at Blackbird.

DeGroff was a highly influential figure and anything he did quickly caught the attention of the bartending community. During his long tenure at the Rainbow Room in the 1980s and ‘90s, he had access to a crushed ice machine. But in his 2002 book, “The Craft of the Cocktail,” DeGroff advised, “You won’t need cracked ice too often, but when you do, just crack large cubes by hand by folding them in a clean dish towel and whacking them with the bowl of a heavy serving spoon.”

By 2006, however, DeGroff and the Lewis bag had found each other. An advertisement that year in the Honolulu Advertiser for a DeGroff class on the history of the Julep, said the entry fee came “with a complimentary Lewis Ice Bag.” And in a 2008 article promoting his new book, “The Essential Cocktail,” DeGroff recommended that ice for a Julep be placed “in a canvas bag, called a Lewis bag.”

Soon after, there were sources other than Franmara for Lewis bags (as they were by 2009 universally called). “Hendrick’s Gin and other companies started to add the Lewis bag to the added-value items they created for the craft community,” recalls DeGroff.

Charlotte Voisey, who worked for Hendrick’s as a brand ambassador in the late aughts, remembers those bags. “Yes, we did indeed make and brand and give out Lewis bags to bartenders,” she says. They were commissioned from a bartender-artist named Allison Webber and embroidered with the Hendrick’s name.

Other liquor companies did the same. The Lewis bag became Lewis swag. And, as you can imagine, doling out free Lewis bags to hundreds of bartenders led to an increase in the use and awareness of Lewis bags. By 2010, barware companies had gotten in on the game. Cocktail Kingdom, among others, began selling their own version of a Lewis bag.

That was probably a good thing. Because, as Abou-Ganim remembers, the actual Lewis bags were not always up to their assigned task. “That lasted about a week in service before it fell apart and we were back to the linen napkins.” (Abou-Ganim eventually produced his own Lewis bag through his Modern Mixologist line.)

Other members of the bartending community took matters into their own hands. Boston bartender Josey Packard, a former seamstress and designer, produced her own Lewis bags for a few years around 2010. She called them Packard bags.

So, the contemporary icon that is the Lewis bag arguably came about through a uniquely American mix of sales hokum, corporate adoption, and outright capitalism, aided by a kind of cocktail-world mind meld.

There are probably chapters to the Lewis bag story that are yet to be uncovered. But, for now, one central mystery remains: Who was Lewis, this person whose name bar types invoke on a daily basis? A doctor? A phantom? Was there ever a Lewis at all?

Only, perhaps, Franmara knows.