GB/T 30766-2014Classification of tea (English PDF)

Foreword

This standard was drafted in accordance with GB/T 1.1-2009 given rules. The standard proposed by China Federation of Supply and Marketing Cooperatives. This standard by the National Standardization Technical Committee of tea (SAC/TC339) centralized. This standard was drafted. China Federation of Supply and Marketing Cooperatives Hangzhou Tea Research Institute, China National Institute of Standardization, Anhui Agricultural University, Fujian Agriculture and Forestry University. The main drafters of this Standard. Weng Kun, Xi Xing Jun, Wan Xiaochun, Zhao Yuxiang, Lili Xiang, Sun Wei Jiang, Zhang Yali. Classification of Tea

1 Scope

China's national classification standard for tea. It specifies the terms and definitions of tea, the principle on which tea is classified, and the resulting categories, and it applies to the production, research, teaching, trade and inspection of tea and to the standards written for it. It is a short document that underlies a very large part of the Chinese tea standards estate, because every product standard for a particular tea depends on the category boundaries drawn here. The classification principle it adopts is processing, not colour, origin or leaf appearance, and that choice is the substance of the document. Tea is defined as a product made from fresh leaves of the tea plant by a specific processing technology, containing no additives, for drinking or eating; fresh leaves are the buds, leaves and tender stems picked from suitable cultivars of Camellia sinensis. The categories are then separated by which processing operations are applied and in what order, and the standard defines each of those operations individually: withering, the controlled loss of water from spread leaf; fixation, the use of heat to destroy enzyme activity; zuoqing, the mechanical bruising of the leaf margin that drives partial oxidation of the polyphenols; yellowing, the heaped warm holding that follows fixing or rolling; fermentation, the enzymatic oxidation of polyphenols under controlled temperature and humidity; and piling, the slow change in heaped made tea under controlled conditions. Where fixation falls in the sequence is what decides the category, because it is the step that stops the leaf's own enzymes. Issued on 9 June 2014 and in force since 27 October 2014.

This standard specifies the terms and definitions of tea, principles of classification and category. This standard applies to tea production, scientific research, education, trade, inspection and related standards.

2 Terms and definitions

The following terms and definitions apply to this document.

2.1 Fresh leaves freshleave Suitable varieties made from Camellia bud tea variety of tea (CamelliasinensisL.O.kunts) picked on, leaves, stems, as various types of tea plus Raw materials workers.

2.2 Tea tea In fresh leaves as raw material, special processing technology, it does not contain any additives, for people to drink or eat products.

2.3 Withering withering Fresh leaves at a certain temperature and humidity conditions even spreading to wilting, distributing water in the process.

2.4 Fixing enzymeinactivation The use of certain temperature, the fresh leaves of the loss of enzyme activity, or said it would deactivate the enzyme process.

2.5 Zuoqing finemanipulation In the mechanical force, fresh leaf margin partially damaged, prompting the partial oxidation of polyphenols, containing the polymerization to produce green leaves red edge process.

2.6 Boring yellow heapingforyelowing The fixing or rolling or after hot bake fresh leaves early accumulation, which will gradually yellowing process under heat action.

2.7 Fermentation enzymaticreaction Under certain temperature and humidity conditions, the fresh leaves inclusions occur in enzymatic oxidation of polyphenols as the main form YE change process.

2.8 Ottawa heap pile Under certain temperature and humidity conditions, the bulk tea led by its contents are slowly changing process.

2.9 Green tea greentea In fresh leaves as raw materials, fixing, rolling, drying and other products made from processing.