STANDARTINFORM prepared an overview of three interstate standards on black tea, green tea and partly fermented tea in the run-up to the World Tea Day. It is traditionally celebrated on December 15.
Tea is classified according to methods of technological processing of tea leaves. It is divided into the following types by its appearance – loose tea, granulated tea, compressed tea.
GOST 32573-2013 «Black tea. Specification» contains requirements for black tea such as its characteristics, raw materials and package. Infusion of compressed and granulated black tea should be bright, clear. It should have tender smell and harsh taste. Sodden tea leaf should have homogeneous brown-red or brown color.
Infusion of compressed black tea should be of dark red or dark brown color. It should have tender smell and harsh taste. Sodden tea leaf should be of dark brown color.
GOST 32574-2013 «Green tea. Specification» provides requirements for green tea including organoleptic features.
This document describes appearance of an infusion of a leaf and granulated green tea. It should have light yellow or light green color, clear or muddy. It should also have tender smell, pleasant harsh taste. Color of a sodden tea leaf should be homogeneous with yellow or green shades.
Infusion of compressed green tea should have red-yellow color while color of a sodden tea leaf should be of dark green color with dark brown shades.
GOST 33481-2015 «Partly fermented tea. Specification» is the newest standard among the above-mentioned described documents. It was implemented for the first time since January 1, 2017.
Partly fermented tea is tea which cannot be classified as green or black one.
Partial fermentation of tea is achieved by quick drying of green leaves after their gathering or slow drying at low temperatures. It is needed to fulfill high-temperature drying for interruption of fermentation.
Infusion of loose and granulated partially fermented tea should be clear or muddy with light yellow, light green or dark red color (bright brown color). It should also have tender smell and pleasant harsh taste.
Compressed tea is clear or muddy infusion of red-yellow color with harsh smell.
Color of a sodden leaf of loose tea and granulated fermented tea is unequal with yellow, green or bright brown shade. Color of compressed tea is dark green with dark brown shade.
Loose green and black tea have homogeneous appearance while partially fermented tea may have tea leaves of various sizes. Granulated tea has spherical or elongated shape while compressed tea should have smooth surface with flat edges.