How to process instant tea

Instant tea is also known as extracted tea. As early as the 18th century, European tea merchants imported a kind of dark cake concentrated from tea extract from China, each piece of about 6-7 grams, which melted into drinking tea, which may be the prototype of today's instant tea. Instant tea is a deep processing product of tea, which comes from a wide range of raw materials and is not restricted by origin. It can be directly obtained from medium and low-grade finished red and green tea, or fresh leaves or semi-products can be used as raw materials. The selection of raw materials is very important in the production of instant tea, which not only has an important impact on the quality, but also closely related to its economic benefits. Different characteristics of regional tea, seasonal tea or different grades of tea can be properly mixed. After the raw materials are selected, the tea should be properly crushed to increase the contact surface between the tea and the solvent and improve the leaching rate of soluble matter. Whether it is black tea instant tea or green tea instant tea, the main production processes are: material acquisition and treatment, extraction, purification, concentration, drying, packaging. The flavor of instant tea is closely related to the extracted components, and the single bucket intermittent extraction method is better. During the extraction, the pre-weighed tea can be poured into the extraction bucket lined with a cloth bag, add a certain proportion of boiling water, cover and extract for 10 minutes and then centrifuge. The experimental results show that the higher the ratio of tea to water, the higher the extraction rate. Generally speaking, the ratio of tea to water is 1 ∶ 6: 12, the extraction times are different according to the age and tenderness of the raw materials, and the extraction quantity increases with the decrease of the tenderness of the raw materials. The extraction method is proper, the aroma of tea is pure and strong, and the soup color is a little mixed with yellow and green. Purification is to remove impurities and sink. At present, there are two main purification methods: one is to use physical methods, such as centrifugation, filtration, etc., and the other is chemical method, which is mainly aimed at the proper chemical treatment of the precipitated part of the cold insoluble substance to promote the solubility of this part of the material. The purified extract is relatively thin, so it is necessary to concentrate and increase the solid to about 20% and 40%, which can improve the drying efficiency. It is also beneficial to obtain low-density granular instant tea. Drying has an important effect not only on the endoplasm of the products, but also on the shape and solubility of the products. Vacuum drying, spray drying and freeze drying are commonly used at present. Among them, spray drying is a commonly used method because of its high efficiency, good solubility and low cost. As a result of drying, the weight of 100ml instant tea is controlled at about 15 grams and the particle size is controlled at 0.2 to 0.5 microns. The final process is the packaging of instant tea. As instant tea is sensitive to odor and easy to absorb moisture, even mild moisture absorption will cause caking and deterioration, loss of aroma and discoloration of soup. When seriously absorbing moisture, it will become pitch-like and undrinkable. For this reason, when packaging instant tea, there must be air-conditioning equipment to control the temperature of the packaging workshop less than 20 ℃ and the relative humidity less than 60%. Lightweight packaging materials are suitable for packaging, such as lightweight bottles, aluminum foil plastic bags and so on. In addition, in the processing of instant tea, in addition to avoiding aroma loss in processing technology, aroma recovery and aroma blending are often needed.