By Noah Kaufman
Updated March 29, 2016
© Photononstop / Alamy

If you paid four dollars for a simple cup of coffee, you must be getting some the world’s finest beans right? Maybe not. For years some roasters have dropped robusta beans, less expensive and generally regarded as tasting unpleasantly bitter (although the beans have some proponents), into their blends along with preferable Arabica beans without telling anyone. In short, they committed coffee fraud. And coffee sellers are far from the only ones— if wine, olive oil and cheese are any indication, food fraud is not a rare occurrence. But authors of a new study in the journal Food Chemistry claim they have discovered a chemical way to figure out whether the blend you bought is the blend you paid for.

Luigi Servillo from the Second University of Naples and his team discovered that a technique called high performance liquid chromatography that relies on passing pressurized liquid through pumps, would reveal the presence of robusta beans because they have 20 times more homostachydrine (a chemical also found in alfafa) than their cousins Arabica. Because homostachydrine moved through the pumps more slowly, it was easy to determine the precise makeup of any particular bag of coffee beans.

This isn’t the sort of thing that any average coffee drinker can undertake at this point—as the Washington Post points out it still requires several thousand dollars worth of equipment. But Servillo says his way is easier and faster than any other method currently utilized.

One thing that isn’t known at this point is exactly how rampant robusta additions and coffee fraud might be, but if Servillo’s method works as advertised, maybe we will all know soon.