Effect of Water Types on the Chemical Properties and Taste in Brewing Tea Soups

Abstract

The ancient Chinese proverb says, water is the “mother of tea”, implying that water plays an important role in brewing tea soups. In this study, the pH, total dissolved solids (TDS) and electrical conductivity (EC) of four types of water, i.e., alkaline water (A), mineral water (M), reverse osmosis water (R), and distilled water (D) were determined. Then, the four types of water, A, M, R, and D were used to brew two types of tea leaves, a white tea and a Pu’er ripe tea, and the pH, TDS and EC of the resulting tea soups were determined for three consecutive brewing intervals of 2, 4 and 6 minutes, respectively. In addition, survey data of tasting the tea soups were collected from a total of 17 respondents for the tea soups brewed by the four types of water, A, M, R and D, respectively. The results showed that A and M were alkaline before brewing tea soups, while the pH of R and D were slightly acidic. However, upon the three consecutive brewing of tea leaves, for white tea, the pH was neutralized by A and M, while R and D remained acidic. For Pu’er ripe tea, the pH was slightly acidic after the brewing by all the water types of A, M, R and D. The TDS for white tea was increased during the second brewing for A and M, and the TDS was decreased in the third brewing for all types of water. For Pu’er ripe tea, the TDS decreased gradually upon three consecutive brewing for all types of water. In general, for the taste of tea soups, the rating scores of 4 and 5 were dominated by alkaline water (A) for both white tea and Pu’er tea. For rating scores of 3, it was dominated by mineral water (M) and reverse osmosis water (R) for both white tea and Pu’er tea. In conclusion, alkaline water (A) appeared to be the preferred water type for brewing tea soups.