It is well known that tap water tastes different due to where the water is tapped, ie its chemical and microbiological compositions. Taste competitions have been performed in different countries to find out the most preferred tap water. With some few exceptions, no studies have been performed in which the taste of tap water is objectively described by analytical sensory methods. The purpose of this study was to evaluate quality of Swedish drinking water from different dwells with emphasis on sensory, chemical and microbiological analyses.
Tap water origin from surface water and from groundwater was collected from the Swedish municipalities Svalöv and Kristianstad. The water samples were collected in 3 points in each municipality: 1. waterworks; 2. near waterworks; 3. far from waterworks. In addition the commercial water Evian was included in the analyses. Analytical sensory analyses (triangle test and quantitative descriptive analysis) were performed along with chemical and microbiological standard analyses according to Swedish drinking water standards.
The results from the triangle test showed significant sensory differences between tap water from surface water and groundwater, as well as in surface water samples collected in different points. The descriptive analysis showed large differences in the perception of bitterness, minerals and off flavours. The perceived differences are in line with earlier studies pointing out inorganic ions as responsible for the taste sensations. The chemical analyses showed that the major difference between the two types of tap water was a higher mineral content and higher alkalinity in the groundwater compared to the surface water. The microbiological analyses did not show any measurable concentrations in any of the samples. There is a need for further research of chemical and microbiological effects on the flavour of tap water, with focus on microorganisms and chemical compounds in low concentrations.