How Do You Decaffeinate Coffee Beans?


Many of us can't start our days without at least one cup of coffee, but we don't really give the magic beans much thought after we drain our mugs. Let's take a look at a few questions you might have about the intricacies of the coffee business.

How do you decaffeinate coffee beans?

There are a number of ways to cut the eye-opening power of a cup of joe, but the methods are basically pretty similar. First, processors use water or steam to swell the green beans, then they extract the caffeine using a solvent. Water, ethyl acetate, methylene chloride, or highly pressurized carbon dioxide strip the caffeine away from the beans, which are then steamed to remove any solvent residues and dried.

Do these methods get all the caffeine out?

Not quite, but it strips away quite a bit. According to U.S. law, any decaffeinated coffee must retain less than 2.5% of its caffeine, while in the EU only 0.1% of decaf beans' dry weight can be caffeine. According to the International Coffee Organization, a cup of decaf has around 3 mg of caffeine in it, while the average 5 oz. cup of drip coffee contains 115 mg.

What happens to all the caffeine that gets stripped from the coffee?

It would be a shame for all that caffeine to go to waste—there are undercaffeinated children in third-world countries, you know—so processors save and sell the jittery gold. Pharmaceutical companies and soft drink makers are the big customers for the extracts; although the kola nut provides a bit of a jolt for your cola, the majority of the caffeine in your soda comes from the addition of caffeine extracted from coffee beans during decaffeination.

Can you age coffee?

You don't want to age that bag of beans you picked up at your local coffeehouse, but coffee producers have aging down to a science. Green coffee beans can take up to 10 years of aging in special warehouses; over time their acidity dies down as their body increases.

A special type of aging in tropical regions results in what's known as "monsooned" coffee. Processors leave beans in open-sided warehouses where they will be exposed to the moist air and winds of monsoon season, which can cut down on acidity and add body in just a few weeks. The most common example of this practice is monsooned Malabar, a prized coffee from southern India.

Has coffee ever been illegal?

The Ottoman Empire cracked down on coffee and coffeehouses at various times, but the most notable ban came under Murad IV, who was the Sultan of the Ottoman Empire between 1623 and 1640 and probably wasn't described as "a fun guy" by any of his subjects. Murad banned tobacco use in the empire and would even walk around in plain clothes looking for smokers. If the emperor caught someone lighting a butt, his majesty would beat the person with his mace.

Tobacco wasn't Murad's only nemesis, though. When he realized that his subjects were congregating in coffeehouses to grouse about having an absolute whack job for an emperor, he banned coffee in the entire Ottoman Empire. Getting caught with a cup of joe earned subjects a beating. Hitting the java a second time got you sewn in a sack and dumped into the waters of the Bosphorus.

Where did the cappuccino get its name?

The delightful concoction of espresso, hot milk, and foam takes its name from the Capuchins, a Roman Catholic order of friars. According to the Oxford English Dictionary, the drink's color resembled the brown robes worn by the Capuchins, so Italian coffee fans began to call the drink the cappuccino.

Where did we get the name "mocha"?

From a port in Yemen. During the 19th century, Mocha was an important port in Yemen where sailors could load their holds with Mocha Java, a tasty blend of local Arabian coffee and beans from the Indonesian island of Java. The renowned blend wasn't cheap, though, so other coffee roasters attempted to replicate the subtle chocolate notes of Mocha Java by adding chocolate directly to lesser beans. Over time, this combination of chocolate and coffee took on the name "café mocha" as a tribute to the port that inspired it.

Why do some coffees market themselves as "arabica"?

Although the name sounds exotic, "arabica" doesn't refer to a special roasting process or preparation. Instead, Coffee arabica is the scientific name of the species of coffee that produces over 60 percent of the world's beans. Arabica coffee is generally regarded as being tastier and less bitter than the other main commercial species, Coffee canephora, but it is more susceptible to disease. While Coffee canephora doesn't have the same yummy taste, it is a hardier plant and produces beans with more caffeine and a full-bodied mouthfeel.

Is there an actual Maxwell House?

There used to be. When it opened in 1869, the Maxwell House Hotel was Nashville's largest and swankiest hotel, and through the early 20th century it pulled in famous guests like Teddy Roosevelt and various members of the Vanderbilt clan. The coffee took its name from the hotel, and for years ad men claimed that the "Good to the Last Drop" slogan originally came from Teddy Roosevelt after he slurped down a cup of the brew. Modern research, though, has suggested that the slogan came from a particularly inspired ad exec. A fire destroyed the Maxwell House in December 1961.