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No. 2419:
Perfecting Coffee

by Roger Kaza

Today, a chemist and his coffee. The University of Houston's Music School presents this program about the machines that make our civilization run, and the people whose ingenuity created them.  

There's something vaguely sinister about addressing a president in Latin. It calls to mind John Wilkes Booth, jumping off the balcony at Ford's Theater after shooting president Lincoln, shouting "Sic Semper Tyranis'—"thus always to Tyrants!" So I wonder what was going through president Franklin Roosevelt's mind when he received a peculiar letter in 1942, as America was entering World War II. It began "minima rex non curat" —"the King does not bother with the details." An insult? But the letter continued: "Sed President curat et minima"—"the president cares even about the details." So what now…flattery? Where was this going? Some sort of covert intelligence? The letter was, after all, from a German-American, Peter Schlumbohm. He held a doctorate in Chemistry from the University of Berlin, but had abandoned this field for the life of an itinerant inventor. He emigrated to the US in 1936 and had made himself busy filing patents by the dozen.

image of Peter Schlumbohm
Dr. Peter Schlumbohm, 1896-1962

The Latin, it turned out, was all for show. The inventor was just doing his best to impress an Ivy-Leaguer. And the "detail" requiring presidential attention? A better cup of coffee for war-weary civilians. Schlumbohm had invented a new coffeepot, known then and now as the Chemex. He'd found a manufacturer willing to make it, Corning Glass Works, but the company needed special permission due to wartime regulations. Schlumbohm wasn't taking any chances; he went straight to the White House.

The Chemex CoffeemakerThe Chemex is a tempered glass vessel that looks like something only a chemist could create. The carafe and filter basket are all one piece, in an hourglass shape. A wooden collar grips the middle, cinched with leather ties — a simple, elegant design that has "Bauhaus" written all over it. The coffee is filtered through special, heavyweight paper filters. But paper coffee filters weren't Schlumbohm's idea. They date back to 1908, when German housewife Melitta Benz experimented with desktop blotting paper to remove the fine sediment from coffee. Before that, coffee-making was a free-for-all. Early recipes instructed you to boil the coffee until it "smelled good." Some used metal filters to separate the grounds. Some poured it through an old sock. Mmm, appetizing. The percolator, patented in 1865, was the quintessential American coffee apparatus through much of the 20th century. It evokes all-night diners, Edward Hopper, and the tarnished pot that lived on the stove. But a percolator boils and re-boils the coffee, producing a strong and sometimes bitter brew. Schlumbohm was convinced that water heated to precisely 200 degrees should be poured—once—over medium ground coffee beans. The chemist's formula was a hit. Today even your local doughnut shop brews coffee this way, more or less.

And the inventor's letter to the president? Fortunately, Roosevelt understood that for a country at war, bad coffee was one sacrifice too many. He personally approved production of the Chemex, and a caffeine-fueled nation has given thanks ever since. So Gratias tibi ago—thank you that you are: Peter Schlumbohm.

I'm Roger Kaza at the University of Houston, where we're interested in the way inventive minds work.

(Theme music)

The impetus for this article came from Charles Panati's book, Extraordinary Origins of Everyday Things, (Harper and Row, 1987).

The Chemex has a cult-like following and there many web pages devoted to it. An iconic design, the Chemex and several other of Schlumbohm's designs are in the permanent collection of the Museum of Modern Art in New York City. 

Chemex's headquarters are located in Pittsfield, Massachusetts. Various retailers carry the Chemex, and vintage units can always be found on eBay.

Wikipedia entry on Peter Schlumbohm.

Photos courtesy the Chemex corporation.