A fine wine has an ideal balance of ingredients. Too much or too little of a component could mean the difference between a wine with a sweet and fruity aroma and one that smells like wet newspaper. To help wineries avoid off-aromas, a team reports in ACS Sensors a sensitive device for detecting a compound that can affect the beverage's fragrance.

Acetaldehyde is frequently found in a lot of places and foods, such as fruits, vegetables and human saliva. When present in high amounts in wine, it produces an unpleasant odor and affects the fermentation process. Therefore, it is important for winemakers to monitor the acetaldehyde levels, which can vary with temperature, pH and oxygen concentrations. Current methods involve trained experts, long processing times and complex equipment. Kohji Mitsubayashi and colleagues propose a sensitive, versatile detector that is more selective than its predecessors.

The team tested for acetaldehyde in nine different wines, both red and white. The new detector produced results comparable to those obtained with traditional methods, but was simpler to operate and produced real-time results. The researchers say that the device could provide wineries with a more practical method for monitoring this make-or-break ingredient.