包種茶製造過程中不良品質生成原因與防止方法之探討

Abstract

1、本年度已完成茶菁日光萎凋後，室內靜置不同攪拌及炒菁程度之11個處理3重複（春、夏、秋）之製茶試驗，目前正進行冬茶茶菁相同處理之製茶試驗。 2、已完成之11個處理所製成之成茶，經官能品評顯示： a、在不攪拌處理，不論其炒菁程度如何，成茶均具有明顯菁味，但其總體滋味和茶菁季節有明顯之相關。 b、在輕攪拌處理，其攪拌二次者之茶湯滋味較四次者淡薄，但均不具澀咸，尤其是攪拌二次者，其茶湯滋味具甘甜口感，唯均具輕微之菁味。 c、在重攪拌處理，其攪拌二次者，茶湯已明顯具有粗澀感，水色深而透明度不足，甘醇度欠佳。 d、在重攪拌處理，其攪拌四次者，水色呈褐色，略帶混濁，而不具透明成，其茶湯粗澀威強烈，具明顯積水之不適口感；查看葉底，則在葉緣四週及先端，均呈現明顯不同程度受傷後之褐變現象，尤以靠近心芽之嫩葉為甚，聞之具有不清之雜味。 e、在不同炒菁程度之處理上，炒菁不足對菁味之產生，不若攪拌不足之明顯，但試驗顯示，炒菁是影響成茶菁味生成原因之一；另在過度炒菁部份，除造成成茶破碎外，並無明顯不良氣味生成，反在水色之明亮度及透明度上具有較佳之表現。 f、從以上試驗結果顯示：茶菁不經攪拌所製成之成茶，除水色淺、滋味淡薄、甘醇度及香氣不足外，並不產生澀感；但茶菁經過攪拌後，如因茶菁萎凋程度與攪拌之時機及輕重之不得當，則易使水色褐變、混濁、茶湯滋味粗澀；依此推測茶菁之不當攪拌（指茶菁之走水程度和攪拌時機與輕重而官），是造成成茶茶湯產生澀感的最主要原因之一。 The effects of solar withering , indoor withering with shaking and panning degree on the sensory quality of Paochung tea were investigated in this study. Offensive odor with strong grassy smell were detected in the samples of without shaking treatments. The same results were obtained independently of panning degree but related producing season significantly. During indoor withering with two times of light shaking indicated more flat and sweet sensory taste than the samples of four times of shaking. Heavy shaking with two times treatments indicated moderate astrigency and brown color of infusion. While the samples of heavy shaking with four times treatments indicated strong astrigency and brown dark color of infusionThe overall quality of heavy shaking with four times treatments were significantly poor than those of light shaking. Degree of panning affects formaton of grassy odor significantly .Samples of light panning indicated strong grassy odor than heavy degree of panning. A clear and bright color of infusion were obtained in the samples of heavy panning treatments but with more broken leaves were detected in the made tea. Factors affect the formation of grassy odor during Paochung tea manufacturing process were presumed causes of without shaking and light panning. The shaking treatments affect significantly overall quality of Paochung tea .The most important reason of formation of astrigency were presumed treatments of improper shaking.