ISO 3103

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ISO 3103 is a standard published by the International Organization for Standardization (commonly referred to as ISO), specifying a standardized method for brewing tea, possibly sampled by the standardized methods described in ISO 1839. It was originally laid down in 1980 as BS 6008:1980 by the British Standards Institution, and a revision was published in December, 2019 as ISO/NP 3103. It was produced by ISO Technical Committee 34 (Food products), Sub-Committee 8 (Tea).

The abstract states the following:

The method consists in extracting of soluble substances in dried tea leaf, contained in a porcelain or earthenware pot, by means of freshly boiling water, pouring of the liquor into a white porcelain or earthenware bowl, examination of the organoleptic properties of the infused leaf, and of the liquor with or without milk, or both.

This standard is not meant to define the proper method for brewing tea intended for general consumption, but rather to document a tea brewing procedure where meaningful sensory comparisons can be made. An example of such a test would be a taste-test to establish which blend of teas to choose for a particular brand or basic label in order to maintain a consistent tasting brewed drink from harvest to harvest.

The work was the winner of the parodic Ig Nobel Prize for Literature in 1999.


A white porcelain tea bowl

To maintain consistent results, the following are recommendations given by the standard:

Pot and bowl

An annex of the standard describes two alternative pots (310 ml and 150 ml) and corresponding bowls (380 ml and 200 ml) “which are in widespread use” for tea tasting, including engineering drawings of their cross sections. The type of pot described is also known as a taster's mug.


"There is no perfect cup of tea: there is only the right one for you."

- Tom Scott, 2018

The protocol has been criticized for omitting any mention of prewarming the pot. Ireland was the only country to object, and objected on technical grounds.

Tom Scott noted that people commonly interpret the standard as a prescriptive way of making the standard tea. He stated that the standard is intended to let people create a reproducible 'okay' tea.

Competing standards

In 2003, the Royal Society of Chemistry published a press release entitled "How to make a Perfect Cup of Tea".

See also


  1. ^ "ISO Standard for sampling tea from containers of all sizes". Archived from the original on 2019-12-29. Retrieved 2017-10-15.
  2. ^ Royal Charter and Bye-laws, 1981, The British Standards Institution
  3. ^ "ISO/NP 3103 - Tea -- Preparation of liquor for use in sensory tests". Archived from the original on 2018-04-10. Retrieved 2018-04-09.
  4. ^ "Fancy a quick cuppa - in 5,000 words?". The Guardian. 2 October 1999. Archived from the original on 23 April 2019. Retrieved 2 November 2013.
  5. ^ "The 1999 Ig Nobel Prize Winners". Annals of Improbable Research. August 2006. Archived from the original on 26 February 2013. Retrieved 2 November 2013.
  6. ^ a b Scott, Tom (2018-04-09). Making an international standard cup of tea. Retrieved 2024-05-28 – via YouTube.
  7. ^ "Feedback column". New Scientist. No. 2207. 9 October 1999. Archived from the original on 29 December 2019. Retrieved 16 May 2017. Nowhere, however, is there mention of the ritual of warming the pot, central to the mystical British Tea Ceremony.
  8. ^ "ISO 3103:1980(en) Tea — Preparation of liquor for use in sensory tests". ISO. Archived from the original on 2020-04-05. Retrieved 2017-09-25. The member body of the following country expressed disapproval of the document on technical grounds: Ireland
  9. ^ "How to make a Perfect Cup of Tea" (PDF). Royal Society of Chemistry. 2003. Archived from the original (PDF) on 2014-08-11.