Yep, you read that last one right: sticks. The researchers say that additives are introduced at the harvest when growers pick the beans and carelessly (or intentionally) gather twigs, sticks, whole coffee berries, and even dirt.
MORE: 9 Incredible Benefits of Coffee
How are these fillers going undetected? "After roasting and grinding the raw material, it becomes impossible to see any difference between grains of lower cost incorporated into the coffee," says Nixdorf, "especially because of the dark color and oily texture of coffee."
Fortunately, Nixdorf and her team have created a way for researchers (and soon commercial venues) to test coffee for impurities. "With our test, it is now possible to know with 95 percent accuracy if coffee is pure or if it has been tampered with." Currently, the team is able to test for corn, barley, wheat, soybeans, rice, beans, açaí seed, brown sugar, and starch syrup. The way the test detects the additives is by comparing pure coffee's carbohydrate content, like a sugar fingerprint, with that of a potentially adultered coffee. Coffee with additives will have a different fingerprint than pure coffee.
Such tests will become more important as we witness continued coffee shortages. The researchers point out that Brazil, which typically produces 55 million bags of coffee, is projected to make only 45 million bags this year because of extensive droughts in January. Droughts like these may be a result of climate change at large. It's estimated that the significantly lower yield means 42 billion fewer cups of coffee. (Want to do something about that? Check out these 3 ways coffee can boost your health and stop global warming.)
But sticks and dirt may not be the worst thing in your coffee. According to Dave Asprey, author of The Bulletproof Diet, coffee is a major source of toxic mold. "The problem isn’t coffee per se, it’s the mold on your coffee," he says. "Cheaper coffee varieties cost less because they use poor quality beans and they allow a higher percentage of damaged (moldy) beans, then companies process them with techniques that add flavor but amplify the amount of toxins." In fact, American coffee has some of the lowest mold standards in the world and is called by Asprey the dumping ground of grounds unfit to be sold in Europe. The biggest symptom of drinking moldy coffee is brain fog.
If you want to cut back, try a non-caffeinated herbal tea to replace at least one cup a day of joe.
The article "What's Really in Your Coffee?" originally ran on RodaleWellness.com.