该研究以保靖黄金茶1号1芽2叶鲜叶为原料试制工夫红茶，考察变温发酵（第一阶段40 ℃ & 第二阶段30 ℃）对黄金茶工夫红茶品质的影响。结果表明：变温发酵加工的工夫红茶色泽黑褐尚润，滋味甜醇、鲜爽，甜香尚高长，汤色红亮，叶底尚红匀；与恒温发酵相比，随着发酵程度的加深，茶汤颜色由红亮向红暗转变更明显，滋味由甜醇向纯和尚甜方向发展，叶底逐渐变暗失去光泽（红亮转为红褐），并随着发酵第一阶段（40 ℃）占据总体发酵时间延长而表现的更加明显；与变温发酵相比，40 ℃、3 h恒温发酵后的氨基酸、茶多酚含量下降最多，与（30 ℃，4 h）处理中茶多酚、氨基酸、可溶性糖等的变化趋势则基本一致，而变温发酵处理后茶黄素的最终含量（0.39%）均高于30 ℃、40 ℃恒温发酵处理；基于感官审评结果与各处理品质成分含量检测结果，综合判定变温发酵处理（40 ℃ 1 h+30 ℃ 2 h）是以黄金茶为原料加工工夫红茶甜醇带鲜特征品质的最佳工艺。

Baojing Huangjincha 1 was used as the raw material to produce congou black tea, and the effects of fermentation at variable temperatures (40 ℃ in the first stage and 30 ℃ in the second stage) on the quality of congou black tea were investigated. The results showed that the color of congou black tea fermented at variable temperatures was dark brown and moist, the taste was sweet, mellow, and fresh, the sweetness was long-lasting, the soup was red and bright, and the leaf bottom was red and even. Compared to fermentation at a constant temperature, the color of the tea soup changed significantly from bright red to dull red, the taste developed from sweet alcohol to pure and sweet, and the leaf bottom gradually became dark and tarnished (turned from bright red to reddish brown); these effects became more prominent as the fermentation time in the first stage (40 ℃) was extended. Compared to variable-temperature fermentation, the content of amino acids and tea polyphenols showed the greatest decrease after 3 h of constant-temperature fermentation at 40 ℃, and changes in the tea polyphenol, amino acid, and soluble sugar contents were generally the same as that observed after fermentation for 4 h at 30 ℃ and a constant temperature. The final content of theaflavins (0.39%) after variable-temperature fermentation was higher than that obtained after fermentation at constant temperatures (30 ℃ and 40 ℃). Based on the results of sensory evaluation and content of quality components in each treatment, variable-temperature fermentation (40 ℃, 1 h+30 ℃, 2 h) is optimal for processing congou black tea with a sweet, mellow, and fresh taste.

国家现代农业（茶叶）产业技术体系建设专项（CARS-19）；国家重点研发计划项目（2017YFD0400802）；湖南省重点研发计划项目（2020NK2047）；湖南省创新平台与人才计划科技特派员服务乡村振兴（2021NK4149）