The Study Of Key Craft And Technical Parameter During The Process Of Guizhou Circle-shaped Tea

Green tea is made from freash tip of tea plant by de-enzyming, rolling and roasting.Guizhou circle-shaped tea is one of teas developed mainly in Guizhou.Its craft was just as belows:Spreading, De-enzyming, Rolling, Dehydration, Shaping, Roasting, Improving aroma.The important processes contained spreading, dehydration, shaping, improving aroma which were definited by for-trial. Basised on current craft and equipments, the trial mainly analyzed the spreading time, dehydration method, the moisture content of dehydration tea leaves, the tea mass each stage during shaping,the effect of spreading time before improving aroma on quality by comparing. In order to provide consult for improving Guizhou circle-shaped tea quality and establishing Guizhou circle-shaped tea processing technology standard. The results were as belows:1.The spreading leaves were depeening as the spreading time. At the time of spreading 14h, the fresh leaves becomed unglossy and soft, which satisfied the green tea processing. At this time, the content proportion of tea polyphenols, amino acids, carbonhydrates and catechins took advantageous to the quality, and the brightness and greeness of unfinished were the best. So during the Guizhou circle-shaped tea processing, spreading thickness of the fresh leaves five-cm, ventilating, aboult 14h were best.2.Compared with tumbling-barrel dehydration method, the dehydration tea leaves were softer and greener, the content of tea polyphenols, amino acids, carbonhydrates were higher, and the dehydration speed was faster by hot-air dehydration. Aboult 42 percentage moisture of dehydration tea leaves was good at the shaping process. It could be concluded that Guizhou circle-shaped tea should kept aboult 42 percentage moisture of dehydration tea leaves by hot-air dehydration.3.Keeping the same condition aboult the other technology parameters of each stage of shaping process, it processed aboult 40min with the tea mass 3-3.5kg on the first stage, aboult 60-70min with the tea mass aboult 5kg on the second stage, aboult 100-120min with the tea mass aboult 8kg on the third stage, which guaranteed well station each stage of shaping process. The change of general matters and colour and lustre were suitable to processing.4.By spreading aboult eight hours after roasted, the content of alcohols and ketones among the aroma components increased. By analyzing the content change of amino acids, carbonhydrates and several chief aroma components, we can reach that the aroma of Guizhou circle-shaped tea was improved by spreading after roasted, and best after spreading aboult 8h.