“I told him about the book I wanted to write: It would be about Ben and Betty and the factory; and Brooklyn; and the waterfront; and the Second World War; and Betty’s brother Abraham, who died in the Philippines and won the Purple Heart and the Silver Star; and Bubba, Betty’s mother, who tried to jump off the roof of her Brooklyn apartment house; and the diner where Ben first worked; and the diner across from the Navy Yard, where Ben invented the sugar packet and Sweet’N Low. And it would be about the history of sugar, which is the history of the West, and how Sweet’N Low is part of that history; and about dieting, and fat people; and packing, and the saccharin ban … and the scandal, and the kickbacks, and the raid by the Feds…”

And it is.

Some readers might tire of Cohen’s style; his words rush and build to a momentum that ebbs and flows but never dies down. His prose is a bit like a booze cruise: It makes you seasick, and a little dizzy, but assuming you haven’t eaten too many shrimp onboard, you still feel really good when you dock. The writing is so warm and generous that it manages the very difficult task of including the reader, making us complicit in what is essentially a very personal story, the story of his family: their dreams and disappointments, their cruelties and loyalties and betrayals.

Cohen has a tendency to glide over history, to sprinkle facts and dates and names like so much garnish. It makes for an exciting read, but sometimes you can’t help wishing that he’d slow down. For instance, when he explains that “the British turned against slavery only when steam power and other advances made the harvesting and refining of sugarcane far less labor intensive. That is, slavery became reprehensible only when slaves are no longer needed,” it’s illuminating, but it also seems like maybe it requires a pinch of salt. The assault of one-sentence epochal assessments is fun, but the freewheeling way in which they’re tossed in also makes you wonder if they’re totally true — they might be, and they probably are, but you’re not quite sure.

Unsurprisingly, Cohen is best on the Sweet’N Low history, which begins not with sugar, but with sugar packets. Shortly after the end of World War II, Ben’s diner business was faltering. So he bought a tea-bagging machine and opened the Cumberland Packing Co. One afternoon, he and Betty were having lunch at Cookie’s in Midwood, Brooklyn. She reached for the sugar dispenser and, according to family lore, realized how unsanitary it was to store sugar that way. All of a sudden, she hit upon the idea of individual sugar packets.

“He was able to reconfigure the machine into the world’s first sugar packer,” Cohen writes. “My grandfather was not the sort of man who invents the new thing. He was the sort of man who takes two things that already exist and combines them in a new and interesting way.” He tried to sell his idea to Domino, but instead, they stole it. (“No thank you, Mr. Eisenstadt,” he was told a month after he demonstrated his invention. “Your machine is quite clever. In fact, we’ve already built one of our own.”) He took on contracts from smaller sugar producers and packed duck sauce, perfume and tokens until one day, in light of the nation’s diet craze, a drug company asked him to create a sugar substitute. There was nothing on the market that tasted good — just vials of Sucaryl, a combination of saccharin and cyclamate that was too sweet in liquid form, and didn’t dissolve properly when crushed into a powder from a pill.

So, in 1957, Ben hired Dr. Kraceur, a chemist. (Cohen compares him to Pete Best, the Beatles’ first drummer — “mostly expunged from lore, but the name endures on the patents.”) The goal was to approximate the texture of sugar and minimize saccharin’s terrible aftertaste. After much experimentation, they settled on adding lactose, a compound sugar that occurs only in milk. It worked beautifully, providing the formula with body and dulling the bitterness of saccharin. The only problem was that the drug company that originally proposed the project was no longer interested. So Ben and Marvin went into business for themselves. They named their concoction Sweet’N Low, not after the Tennyson poem of the same name, but after the hit 1919 song that used the poem’s words. Aunt Barbara provided the famous musical notes.

The days of the family business are going by the wayside; “Sweet and Low” is a story of an era that may no longer exist, of a time when an accidental invention literally changed the world. As Cohen writes, “We are in the age of the genome and the genetic code, the double helix twisting towards the sun. The age of the accidental discovery is over.” Splenda, which leads the artificial sweetener market, is the product of purposeful genetic engineering, the rearrangement of the sugar molecule that passes through the body unabsorbed because the body can’t recognize it. (Creepy.) And, as you might expect, it’s distributed by a huge multinational corporate behemoth — Johnson & Johnson. (Although, to be fair, J&J offered to sell the sucralose patent to Marvin in 1998; characteristically, he refused.)

When all the powders and packets and dirty dealings are stripped away, “Sweet and Low” is a snapshot of a kind of business that is rarer and rarer — an independent, mismanaged enterprise, marred by petty squabbling, jealousies and childhood rivalries, that muddles along, managing to bring in, as of 2004, $66 million in sales. Somehow Cumberland is still standing, although the Brooklyn Domino refinery has been shuttered up and shut down for a couple of years now. It’s exciting to see the double helix reach the sun, but I hope there’s still room on the table for our old friend sugar. Building a mosque out of Splenda just doesn’t have the same ring to it.