1、BSI Standards PublicationPD ISO/TR 12591:2013White tea DefinitionCopyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-PD ISO/TR 12591:2013 PUBLISHED DOCUMENTNational forew
2、ordThis Published Document is the UK implementation of ISO/TR12591:2013.The UK participation in its preparation was entrusted to TechnicalCommittee AW/8, Tea.A list of organizations represented on this committee can beobtained on request to its secretary.This publication does not purport to include
3、all the necessaryprovisions of a contract. Users are responsible for its correctapplication. The British Standards Institution 2014. Published by BSI StandardsLimited 2014ISBN 978 0 580 75783 9ICS 67.140.10Compliance with a British Standard cannot confer immunity fromlegal obligations.This Published
4、 Document was published under the authority of theStandards Policy and Strategy Committee on 28 February 2014.Amendments issued since publicationDate Text affectedCopyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or netwo
5、rking permitted without license from IHS-,-,-PD ISO/TR 12591:2013 ISO 2013White tea DefinitionTh blanc DfinitionTECHNICAL REPORTISO/TR12591First edition2013-12-15Reference numberISO/TR 12591:2013(E)Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not
6、 for ResaleNo reproduction or networking permitted without license from IHS-,-,-PD ISO/TR 12591:2013ISO/TR 12591:2013(E)ii ISO 2013 All rights reservedCOPYRIGHT PROTECTED DOCUMENT ISO 2013All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized other
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8、se postale 56 CH-1211 Geneva 20Tel. + 41 22 749 01 11Fax + 41 22 749 09 47E-mail copyrightiso.orgWeb www.iso.orgPublished in SwitzerlandCopyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without lic
9、ense from IHS-,-,-PD ISO/TR 12591:2013ISO/TR 12591:2013(E) ISO 2013 All rights reserved iiiContents PageForeword ivIntroduction v1 Scope . 12 Terms and definitions . 13 Origins of white tea 13.1 Historical origins of white tea 13.2 Descriptive names: black, green, and white teas 13.3 Plant source an
10、d parts used 23.4 Processing stages 23.5 Sensory analysis . 24 Recommendations 24.1 General recommendations 24.2 Chemical recommendations 3Annex A (informative) Appearances of different subtypes of white tea 4Bibliography 6Copyright British Standards Institution Provided by IHS under license with BS
11、I - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-PD ISO/TR 12591:2013ISO/TR 12591:2013(E)ForewordISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of pr
12、eparing 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, i
13、n 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/IE
14、C Directives, Part 1. In particular the different approval criteria needed for the different types of ISO documents 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).Attention is drawn to the possibility t
15、hat some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. Details of any patent rights identified during the development of the document will be in the Introduction and/or on the ISO list of patent
16、declarations received (see www.iso.org/patents).Any trade name used in this document is information given for the convenience of users and does not constitute an endorsement.For an explanation on the meaning of ISO specific terms and expressions related to conformity assessment, as well as informati
17、on about ISOs adherence to the WTO principles in the Technical Barriers to Trade (TBT) see the following URL: Foreword - Supplementary informationThe committee responsible for this document is ISO/TC 34, Food products, Subcommittee SC 8, Tea.iv ISO 2013 All rights reservedCopyright British Standards
18、 Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-PD ISO/TR 12591:2013ISO/TR 12591:2013(E)IntroductionTea is grown and manufactured in numerous countries of the world and is blended and/or drunk
19、in many more. There is some confusion as to the origins, appearance, and processing parameters for white tea and how this might or does differ from green, black, and other types of tea.The desired characteristics of white tea and the resulting liquor brewed from this depend upon a number of factors
20、including the parts of the plant used for manufacture and how they are processed.The objectives of this Technical Report are to specify the plant source and parts from which the white tea is manufactured and to set requirements for production methods and certain physical and chemical characteristics
21、 which, if met, are an indication that the tea had been subjected to good production practice. It is a matter for the parties concerned whether to apply the recommendations of this Technical Report as the basis of an International Standard for white tea.The level of catechins in white and green teas
22、 is much higher than in black tea and can be a useful discriminant between these types of tea and black tea. Differentiation between green and white tea might need the use of ratios of the various chemical components, among others. ISO 2013 All rights reserved vCopyright British Standards Institutio
23、n Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-PD ISO/TR 12591:2013Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or netw
24、orking permitted without license from IHS-,-,-PD ISO/TR 12591:2013White tea Definition1 ScopeThis Technical Report contains information regarding the manufacture and chemical analysis of the tea referred to as white tea in international trade.It provides an internationally agreed definition of white
25、 tea based on the plant source and production methods used. It explains how the application of these criteria has an effect on the physical and sensory attributes of white tea.It does not apply to flavoured white tea, blended white tea, and decaffeinated or soluble extracts of white tea.2 Terms and
26、definitionsFor the purposes of this document, the following terms and definitions apply.2.1white teatea derived solely and exclusively, and produced by acceptable processes, by harvesting and a single withering/drying stage of the bud or bud and tender shoots (one to three leaves) of varieties of th
27、e species Camellia sinensis (L.) O. Kuntze known to be suitable for making tea for consumption as a beverage3 Origins of white tea3.1 Historical origins of white teaThis type of tea has its historical roots in China, more specifically in the Fujian province of South West China and was originally pro
28、duced from two subvarieties of Camellia sinensis sinensis, which were var. Zhenghe dai bai and var. Fuding dai bai.White tea should not be defined by its geography and although white tea has been produced for many decades in this region, it is now produced in other regions of China as well as other
29、international tea-producing countries. The harvesting and processing methods used in all regions are generally based upon those originally developed in the Fujian region.3.2 Descriptive names: black, green, and white teasBlack and green are colour descriptions of bulk property of the dry tea. The co
30、lour of the dry leaf matter is a reflection of the level of aeration (formerly known as fermentation) that the material receives during primary processing, with green teas having minimal/no aeration and black teas, medium to extensive aeration. This colour is usually also reflected in the liquor, wi
31、th green teas producing pale yellow-green to amber colour liquors and black teas producing pale amber to deep brown/black liquors. The tastes of these types of tea are also distinctive enough to be easily differentiated by skilled tea tasters.White tea is named as such not for the bulk colour of the
32、 leaves but after the fine white hairs that cover the surface of leaf buds and the underside of the leaf surface. This lends an appearance of whiteness to the leaf material. This is most apparent in grades where the bud alone is harvested, e.g. longevity eyebrow. Other grades such as Pai Mu Dan do n
33、ot have such obvious leaf hairs but are still considered white tea due to the processing methods used.TECHNICAL REPORT ISO/TR 12591:2013(E) ISO 2013 All rights reserved 1Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction o
34、r networking permitted without license from IHS-,-,-PD ISO/TR 12591:2013ISO/TR 12591:2013(E)3.3 Plant source and parts usedWhite tea is produced solely and exclusively, from the leaves, buds and tender shoots of varieties of the species Camellia sinensis (L.) O. Kuntze, known to be suitable for maki
35、ng tea for consumption as a beverage.More specifically, there are two main subtypes of white tea which differ significantly in their appearance based upon the raw material harvesting/selection and, as such, are worth noting here. The two main subtypes area) bud-only type white tea with designations
36、such as longevity eyebrow and silver needle which are only the unopened buds of the tender shoots of the tea bush, andb) bud-plus-leaf type white teas such as Pai Mu Dan (Bai Mu Dan), also known as White Peony, which are the unopened buds harvested together with the first, second, and even third lea
37、f of the tender shoot.See Annex A for figures which highlight these differences.3.4 Processing stagesWhite tea is the least processed of all tea types. Once the raw material has been harvested, the tea is laid out on some form of assembly, allowing the free passing of air, and the material is slowly
38、 dried. No enzyme inactivation (steam or pan firing), rolling, or comminution (cutting) is carried out. The tea leaf is simply withered and dried in a single processing stage either in the sun, under cover, or a combination of both. The application of artificially heated air to accelerate the drying
39、 is increasingly common.3.5 Sensory analysisThe discrimination by sensory analysis between green and white tea is organoleptically possible by skilled tea tasters, who base their judgements on their previous experience of white tea. Account is taken of characteristics including the appearance of the
40、 tea before the preparation of liquor (such as shape, colour, cleanliness, and evenness), the appearance of the infused leaf, and the appearance, odour, and taste of the liquor. The challenge for people and authorities in the field of tea analysis and purchase is the lack of an agreed vocabulary on
41、green (and white) tea tasting terms. A key discriminator for white tea is that sensory notes which are indicative of enzyme inactivation through steam (wet heat) or pan-firing (dry heat), associated with green teas, should be entirely absent in white teas. This is a general challenge for green and w
42、hite tea sensory analysis.The sensory attributes of any tea are a combination of the inherent flavour attributes of the raw materials from the country of origin as well as the type of processing. White teas from non-Fujian origins can, therefore, have significant additional flavours versus tradition
43、al Chinese white teas. This should also be taken into consideration during organoleptic analysis.4 Recommendations4.1 General recommendationsThe tea should be free from taint and should have the characteristics, appearance, colour, and taste of white tea when examined by sensory analysis.The tea sho
44、uld be free from any additives such as colouring agents and flavourings.NOTE Methods of sensory analysis are described in a series of International Standards.The tea should be clean and free from extraneous matter when inspected visually.2 ISO 2013 All rights reservedCopyright British Standards Inst
45、itution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-PD ISO/TR 12591:2013ISO/TR 12591:2013(E)4.2 Chemical recommendationsThe international investigation into total polyphenols (and catechin contents) in
46、black, green, and white tea gave only limited analytical information available on white tea utilizing the agreed ISO methods, with analysis on only 12 samples being submitted; from these data, only five samples were taken forward when outlier laboratories were removed from the data sets. This work h
47、as been published in the scientific literature.1Further work is required on white tea to include more samples, additional origins, and, potentially, other chemical components such as caffeine and theanine. Inclusion of these and investigation on comparing ratios of these components can prove useful
48、in further defining white tea based upon chemical composition. ISO 2013 All rights reserved 3Copyright British Standards Institution Provided by IHS under license with BSI - Uncontrolled Copy Not for ResaleNo reproduction or networking permitted without license from IHS-,-,-PD ISO/TR 12591:2013ISO/TR 12591:2013(E)Annex A (informative) Appearances of different subtypes of white teaFigure A.1 Bud-only grade of white tea4 ISO 2013 All rights reservedCopyright British Standards Institution Provided by IHS under license
