ISO 3103

ISO 3103 is a standard published by the International Organization for Standardization (commonly referred to as ISO), specifying a standardized method for brewing tea. It was originally laid down in 1980 as BS 6008:1980 [http://www.standardsdirect.org/standards/standards4/StandardsCatalogue24_view_4605.html BS 6008:1980 Method for preparation of a liquor of tea for use in sensory tests] standardsdirect] . 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, containing 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 liquid with or without milk or both.

This standard is not meant to define the proper method for brewing tea, but rather how to document tea brewing procedure so sensory comparisons can be made. An example of such test is a taste-test to establish which blend of teas to choose for a particular brand 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.

Details

To maintain consistent results, the following are recommendations given by the standard:
* The pot should be white porcelain or glazed earthenware and have a partly serrated edge. It should have a lid that fits loosely inside the pot.
* If a large pot is used, it should hold a maximum of 310 ml (±8 ml) and must weigh 200g (±10g).
* If a small pot is used, it should hold a maximum of 150 ml (±4 ml) and must weigh 118g (±10g).
* 2 grams of tea (measured to ±2% accuracy) per 100ml boiling water is placed into the pot.
* Freshly boiling water is poured into the pot to within 4-6mm of the brim.
* The water should be similar to the drinking water where the tea will be consumed
* Brewing time is six minutes.
* The brewed tea is then poured into a white porcelain or glazed earthenware bowl.
* If a large bowl is used, it must have a capacity of 380ml and weigh 200g (±20g)
* If a small bowl is used, it must have a capacity of 200ml and weigh 105g (±20g)
* If the test involves milk, then it can be added before or after pouring the infused tea.
* Milk added after the pouring of tea is best tasted when the liquid is between 65 - 80°C.
* 5ml of milk for the large bowl, or 2.5ml for the small bowl, is used.

Competing standards

In 2003, the Royal Society of Chemistry published a news release entitled "How to make a Perfect Cup of Tea." [cite web| url=http://www.rsc.org/pdf/pressoffice/2003/tea.pdf| title=How to make a Perfect Cup of Tea| format=PDF| year=2003| publisher=Royal Society of Chemistry]

References

External links

* [http://www.iso.ch/iso/en/CatalogueDetailPage.CatalogueDetail?CSNUMBER=8250&ICS1=67&ICS2=140&ICS3=10 ISO 3103 at iso.ch]
* [http://www.iso.ch/iso/en/CatalogueListPage.CatalogueList?ICS1=67&ICS2=140&ICS3=10&scopelist= Other tea related documents from iso.ch]
* [http://sub.spc.org/san/docs/BS6008.pdf BS6008]