By Barbara Dufrene
Since 1970 the International Organization for Standarization (ISO) has established more than 20 standards for tea. The latest of these offers the first industry wide science-based definition of white tea.
ISO’s technical paper describes the manufacturing process and provides a chemical analysis creating an internationally agreed definition of white tea. The document “White Tea - Definition” (ISO TR 12951) is ISO’s first attempt to establish criteria for specialty teas. Next up is standards defining matcha.
Since its inception ISO’s tea subcommittee (TC34/SC8) has been closely associated with the British Institute for Standards (BSI). BSI operates as the committee secretariat. The chair has always been a British tea expert. Dr. Peter D. Collier served from from 1990 to 2004, and Dr. Andrew Scott since 2004. Mao Limin of China is the current vice chair.
The committee’s mandate is to facilitate international trade; ensure that consumer expectations are met regarding product quality and safety and provide guidance and a common understanding of good manufacturing practices.
To meet these targets a huge amount of work has been carried out by ISO tea, with the core standards for black and soluble tea having been achieved before 2000. Green tea standards followed in 2013.
In the new millennium tea production has reached unheard of volumes, exceeding 5 million metric tons in 2014, of which 40% is grown in China. Since 1990 Western consumer markets also have witnessed continued development of tea products including ready-to-drink tea in bottles and cans, instant teas, tea concentrates, tea in single-serve capsules, and tea-based soft drinks.
In parallel there is continued healthy growth in the premium leaf tea niche market, both in the West and at origin, where wealthy Chinese and overseas Chinese pay huge sums for small specialty pickings.
As new priorities emerge, determining the appropriate definitions for specialty tea is a priority in meeting consumer expectations and to ensure a level playing field for tea producers and the tea trade.
In 2008 it was the Chinese delegation, at the ISO’s 22nd Plenary Meeting in Hangzhou, China, who insisted on initiating work to define specialty teas. The White Tea Standard is the first approved within that new scope.
Encouraged by “a levelling off of the playing field after the approval of an international definition of white tea” Kotaro Tanimoto, representing the Japanese Tea Exporters Association, subsequently submitted a request for a definition of matcha based on work by Japan’s Standards Committee.
Japanese tea producers report they are struggling to increase supply, while facing a lot of lower-priced competition from green tea powder producers in China and Korea, according to Tanimoto. His recommendation to define matcha was accepted in June at the ISO’s 25th Plenary Meeting in Shizuoka City, Japan.
ISO and Tea: 45 Years of Standards
ISO 3720: Defined black tea quality approved eight testing methods to measure basic tea parameters (parameters have since been updated four times).
ISO 3103: Defined a method of preparation of tea liquor for use in sensory tests. ISO 1839 also established tea sampling methods that same year.
ISO 6078: Established a universal vocabulary/ glossary of terms used to describe tea.
ISO 6079: Agreed to four standard test methods defining Instant tea, a major ingredient in the booming RTD tea sector.
ISO 10727: Provides the means to determinate caffeine content in both instant and leaf tea.
ISO 14502: Determination of substances and characteristics of green and black tea, including total polyphenols using a colorimetric method.
ISO 11287: The above paved the way for a definition of green tea using a combination of chemical analysis and manufacturing procedures.