Although coffee consumption is at an all-time high, it's also in shorter supply. In response, some coffee producers are adding filler ingredients to their coffees, resulting in a lower quality product that might not taste as good.

These additives include corn, wheat, soybeans, brown sugar, barley, twigs and dirt. These ingredients are all natural, however, someone with a soy or wheat allergy should be careful of what they drink. Also, who wants to drink a cup of coffee mixed with twigs and dirt?

Suzana Lucy Nixdorf, a researcher at Universidade Estadual de Londrina in Brazil, created a test to weed out the additives and find the coffees that contained them.

Although a scientist can spot fake coffee by looking at it under a microscope, if the beans are already roasted and ground, it's impossible to spot the fillers because they blend in with the coffee. Taste can sometimes be used as a determining factor, but not always. So Nixdorf created a test that uses something called liquid chromatography. After brewing coffee and sending it through a pressurized pump and paper filter, each ingredient takes on a specific stain, separating it from the actual coffee.

In experiments, Nixdorf's test correctly stained the filler ingredients with an accuracy of 95 percent.

Part of the problem the coffee industry is facing is an increasing demand for the product, but a shorter supply of it. Scientists believe the shorter supply is the result of climate change. In Latin America, wetter conditions recently led to a rise in "coffee rust," a fungus that destroys crops. In Brazil, the opposite occurred: severe drought destroyed many coffee crops.

Not only does this raise prices for coffee, but it also encourages producers to add in the filler ingredients.

"Less coffee makes prices rise," says Nixdorf. "You pay for coffee, but you aren't really getting coffee. That's the problem."

So how can you make sure you're getting real coffee in your cup? Unfortunately, Nixdorf's test can only be done in a lab, so your only recourse is to buy whole-bean coffee or buy ground coffee from trusted brands and coffee shops, like Starbucks, who recently started their own coffee farm.

Coffee is one of the most consumed beverages in the world. Over 50 percent of Americans over the age of 18 drink coffee daily. Not only does coffee increase alertness, thanks to its caffeine, but it also offers health benefits. Just make sure that your coffee is actually just that: coffee.