Under ISO 3103, how long is black tea brewed for sensory testing?

Under ISO 3103, how long is black tea brewed for sensory testing? The answer is six minutes.

ISO 3103 specifies a controlled method for preparing tea liquor so tasters can compare teas consistently. For black tea, the standard calls for six minutes of brewing after freshly boiling water is added. The procedure is designed for sensory evaluation, not as a universal recommendation for making an everyday cup.

The method uses measured tea and water in a white porcelain or glazed earthenware pot, followed by pouring the infusion into a matching bowl for examination. The standard specifies two pot sizes, including a large pot holding about 310 millilitres and a small pot holding about 150 millilitres. It also uses approximately 2 grams of tea per 100 millilitres of water.

The timing differs for green tea: leafy green tea is brewed for five minutes, while fanning green tea is brewed for three. That distinction explains why five and three minutes are plausible distractors, but neither is the ISO 3103 time for black tea. The standard originated as British Standard 6008 in 1980.