sentences:  These differences can be tasted by a trained taster in order to ascertain the quality prior to sale or possibly blending tea.The ISO 3103 standard describes a standardised method for brewing teas in order to make meaningful sensory comparisons between them.It is not a particularly useful standard for many teas, however, requiring a six-minute brewing time and boiling water, neither of which are recommended for green teas (usually brewed at < 90 °C and for under 3 minutes).