National foreword

This British Standard is the UK implementation of ISO 18449:2025. It supersedes BS ISO 18449:2021, which is withdrawn.

The UK participation in its preparation was entrusted to Technical Committee AW/8, Tea.

A list of organizations represented on this committee can be obtained on request to its committee manager.

Contractual and legal considerations

This publication has been prepared in good faith, however no representation, warranty, assurance or undertaking (express or implied) is or will be made, and no responsibility or liability is or will be accepted by BSI in relation to the adequacy, accuracy, completeness or reasonableness of this publication. All and any such responsibility and liability is expressly disclaimed to the full extent permitted by the law.

This publication is provided as is, and is to be used at the recipient’s own risk.

The recipient is advised to consider seeking professional guidance with respect to its use of this publication.

This publication is not intended to constitute a contract. Users are responsible for its correct application.

Compliance with a British Standard cannot confer immunity from legal obligations.

This British Standard was published under the authority of the Standards Policy and Strategy Committee on 31 July 2025.

Foreword

ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization.

The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IEC Directives, Part 1. In particular, the different approval criteria needed for the different types of ISO document should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives).

ISO draws attention to the possibility that the implementation of this document may involve the use of (a) patent(s). ISO takes no position concerning the evidence, validity or applicability of any claimed patent rights in respect thereof. As of the date of publication of this document, ISO had not received notice of (a) patent(s) which may be required to implement this document. However, implementers are cautioned that this may not represent the latest information, which may be obtained from the patent database available at www.iso.org/patents. ISO shall not be held responsible for identifying any or all such patent rights.

Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.

For an explanation of the voluntary nature of standards, the meaning of ISO specific terms and expressions related to conformity assessment, as well as information about ISO’s adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see www.iso.org/iso/foreword.html.

This document was prepared by Technical Committee ISO/TC 34, Food products, Subcommittee SC 8, Tea.

This second edition cancels and replaces the first edition (ISO 18449:2021), which has been technically revised.

The main changes are as follows:

the Introduction has been revised;
terms 3.1.1.5 and 3.1.1.6 have been added;
Annexes A to G have been added to provide illustrated examples.

Any feedback or questions on this document should be directed to the user’s national standards body. A complete listing of these bodies can be found at www.iso.org/members.html.

Introduction

Tea is grown and manufactured in numerous countries around the world and is blended or drunk in many more. Green tea is produced using fresh tea leaves, which can be from more than one garden or region. There are many factors that impact the flavour of green tea, including the water used for brewing, the preparation method of the liquor and individual tastes.

The two International Standards for black tea, which provide a vocabulary and requirements, ISO 6078^[1^] and ISO 3720^[2^], respectively, were first published in the 1980s and are still used today, with the latter having been revised several times. They have played an important role in improving the global black tea trade.

Currently, an increasing number of consumers enjoy drinking green tea not only for its impact on health, but also for its special appearance and flavour. ISO 11287^[3^] provides the requirements for green tea, and this document provides the accompanying vocabulary. It has been developed primarily for use by the tea trade, to enable clear and open communication, and also to ensure that consumers are not misled.

The quality of green tea is usually assessed by professional tea tasters, whose judgement is based on their experience of tea evaluation, the conditions of the producing area and the preferences of the consuming country. Five factors are considered when evaluating the quality of green tea: the appearance of the dry tea leaf (such as shape, colour, cleanliness and evenness), the appearance and the odour of the infused leaf, and the colour and the taste of the tea liquor. Usually, a chemical analysis of tea is undertaken only when it is specifically requested or abnormal characteristics are exhibited.

This document comprises a selection of terms used in the tea trade all over the world, covering not only the processing of green tea but also the essential aspects of assessing green tea for commerce. Corresponding images for these terms are provided in Annexes A to E. Flavour wheels of taste and aroma are presented in Annexes F and G, respectively, to facilitate the intuitive understanding and application of the terms.

Many of the terms in current use for green tea are synonymous or very similar in meaning, and considerable divergences in usage exist.

Accordingly, this document aims to establish recognized definitions for the terms, and thus eliminate differences in usage, and also to encourage a reduction in the number of terms used overall.

The terms are classified as follows:

classification of green tea (see 3.1);
dry leaf (see 3.2):
- appearance (see 3.2.1);
- colour (see 3.2.2);
quality of liquor (see 3.3):
- taste (see 3.3.1);
- colour of liquor (see 3.3.2);
infused leaf (see 3.4):
- appearance (see 3.4.1);
- aroma (see 3.4.2).

1 Scope

This document defines terms for classifying and assessing green tea for commerce.

2 Normative references

3 Terms and definitions

3.1 Classification of green tea

3.2 Dry leaf

3.3 Quality of liquor

3.4 Infused leaf

Bibliography

BS ISO 18449:2025

Green tea. Vocabulary

Current

Published:

31 Jul 2025

1 Scope