With the ever-increasing consumption of coffee due to the availability of small home espresso machines, shelf life and consistency of flavor are becoming more important for brand quality in a competitive market.

Many of the key factors that influence coffee taste correlate with chemical properties that can be measured. These include pH, titratable acidity, refractive index, and caffeine. Historically, many of these analyses have included long, manual sample preparation processes using the time-consuming, liquid chromatography (LC) technique.

This Application Note looks at a faster, simpler, alternative method for analysis of key quality parameters in coffee using a single titration platform: OMNIS. 

Coffee is primarily acidic, with most roast extracts displaying a pH of approximately five. When coffee is too acidic, it can taste sour and be harsh on the palette. When shifting to the alkaline end of the pH scale, the flavor then becomes bland and lifeless.

Different coffee beans require different amounts of roasting, depending on the bean origin and the level of acidity, to achieve the consistent flavor expected from the brand line. By analyzing the pH and acidity of coffee brewed under consistent conditions, it is possible to judge the final flavor of a roast. This is most beneficial to roasters of large volumes of coffee beans, or to those who supply products with expected flavor profiles (e.g. instant coffee pods).

The analysis of pH and acidity in brewed coffee is quite simple and very similar to the procedure used for juices and soft drinks.