ISO 3103:1980 (ISO standard for tea making) (sub.spc.org)

This standard basically dictates how to prepare 'tea' so that an expert tea taster can evaluate its quality. At the end of the day the tests are subjective.

It never amazes me how many of these tests and standards have been produced and in many cases stop progress.

Sometimes I wonder what would have happened if there was a 'Standard for Web Applications' although things came close enough with accessibility laws.

6 minutes steeping for tea? That's an awful lot. Good tea is usually steeped for 3-5 minutes.

And not a word about brewing temperature? Nothing about the quality of the water and its TDS? Seems like a pretty loose standard.