Sensory properties of Danish municipal drinking water as a function of chemical composition

- Exploratory descriptive sensory analysis is used to characterize Danish drinking water.
- Saltiness has a positive linear correlation with TDS and Na concentration.
- The attribute fresh is negative linear correlated with TDS and Na concentration.
- Fresh drinking water is mainly a result of low salt concentrations.
- Drinking water from sandy aquifers gives fresh drinking water.

Studies have shown that drinking water of good sensory quality have total dissolved solid (TDS) concentrations between 100 and 450 mg L− 1. However, such studies have only investigated the overall sensory quality of water and not the different sensory attributes. Little is known about the taste and mouthfeel attributes of drinking water in relation to the chemical composition. The purpose of this study was to determine the variation in sensory attributes of Danish drinking water and the relation to the chemical composition. Groundwater samples were collected from 20 waterworks with uplands and aquifer reservoirs characteristics covering the main variation in geochemistry and land use. The groundwater samples' inorganic chemical composition was determined and a trained panel determined sensory attributes and their intensities. Identified sensory attributes listed with decreasing intensity were: moist, fresh, salty, chalky, hard, astringent, metallic, bitter, sweet and sour. The main sensory variation between samples was caused by the saltiness and this attribute was negatively correlated to all other impressions especially moistening. The saltiness had a strong linear positive correlation to the TDS, conductivity and Na concentration (R2 = 0.72-0.92) whereas the descriptor fresh was negatively linear correlated to these parameters (R2 = 0.76-0.81). The descriptors, fresh and moist, seem mainly to be a result of low salt concentrations which characterises samples from aquifers at the glacial outwash plains of western Jutland and elevated seabeds of northern Jutland.