A New App Can Tell You When Your Beer is Skunked

Nothing ruins the fun of summer drinking like being stuck with a big case of skunked beer. Even warm beer can eventually be cooled, but once it has reached the perma-skunked point of no return, there's not a whole lot you can do about it; other than shut up and drink it and squint your eyes every time you take a sip.

While there are a number of factors that can lead to skunky beer—like green glass bottles, for instance—more often than not, the main culprit is a chemical compound called furfural. And in order to detect furfural, beer makers have had to rely on an expensive and time-consuming process called chromatography.

But now, thanks to chemists at the Complutense University of Madrid, that process just got a whole lot easier. Researchers Elena Benito-Peña and María Cruz Moreno-Bondi have developed a way of detecting skunkiness with just a sensor and a cell phone app. The chemists created sensors which change from yellow to pink when they come into contact with furfural.

"We have incorporated an aniline derivative into the sensor material which reacts with the furfural and produces a pink cyanine derivative that allows us to identify the presence of the marker in the sample. The intensity of the colour increases as the concentration of furfural in the beer rises and, thus, as more time passes since the beer was produced," Benito-Peña said in a press release.

Then, using an Android app, the amount of furfural can be measured simply by taking a picture of the sensor with a smartphone. But why not just use the more reliable and even cheaper sensor—the human nose—to detect skunky beer? The practical answer is that with 200 billion liters produced every year, we should probably stick to drinking it instead of smelling it.

Trial runs of this method have been "very satisfactory" according to Benito-Peña, and their results could have a huge impact on the beer industry, since skunkiness could be tracked down on the production line, and not in your summer cooler.