A cheaper way to detect dimethyl sulfide in beer using smartphones has been found by scientists.

A new experimental measurement tool, created by scientific researchers at the University of Santo Tomas, Manila, Philippines, will allow the assessment of dimethyl sulfide (DMS) concentrations in beer through the use of “smartphone-based colorimetry” and a “paper-based analytical device (PAD),” say the researchers. This is much simpler and cheaper than using gas chromatographic analysis which is the current preferred method.

DMS contributes significantly to the flavour profile of beer and brewers and beer drinkers have historically noted how its presence is desirable at low concentration levels, but that it becomes an off-flavour at high concentrations and can result in unpleasant cooked cabbage and sweetcorn aromas. Consequently, breweries like to analyse the DMS content of beer products to ensure consistent flavour quality and consumer satisfaction.

The scientists point out that “among the salient flavour components of beer are the sulfur-containing compounds, the most abundant of which is DMS. Though present at μg L−1 level concentrations, DMS significantly contributes to the aroma and flavour profile of the beer. Its level in most beer products is usually maintained below its sensory threshold of 30 μg L−1; however, lager beers contain DMS levels of 50 to 100 μg L−1. Beyond this concentration level, the powerful cabbage-like odour of DMS becomes noticeable, causing off-flavour and lowering the sensory quality of the beer.”

According to the scientists, using a smart phone to capture a digital image of the PAD, allows DMS concentration to be effectively determined by its RGB colour value. “The results of smartphone-based colorimetry agreed well with the results of chromatographic analysis of DMS in lager and all-malt beer samples,” says the researchers, “and now offered up a less expensive way of measuring DMS quickly and easily, especially for smaller beer producers.”