下关沱茶7581是一款经典的熟普洱茶，其前身为昆明茶厂产品，后因昆明茶厂并入下关茶厂，现由下关茶厂生产。以下是具体介绍：
名称由来：“75”代表1975年研发的配方，“8”代表所用毛茶原料等级为8级左右，“1”代表昆明茶厂。
外观特征：通常为砖形紧实，色泽褐红，有时带点金毫，条索清晰。
口感风味：口感醇厚顺滑，回甘明显，有“下关味”特色，堆味相对较淡。新茶茶气较重，陈化时间长的则更柔和、醇和，干茶有陈香，冲泡后带有独特的木香和药香，汤色红浓明亮。
地位与特点：7581是普洱熟茶史上首款唛号茶，被称为“熟茶之母”，以其稳定的品质和较高的性价比，成为资深茶客日常饮用、新晋茶友入门的臻选。
Xiaguan Tuocha 7581 is a classic ripe Pu'er tea, which was originally produced by Kunming Tea Factory. Later, Kunming Tea Factory was merged into Xiaguan Tea Factory and is now produced by Xiaguan Tea Factory. Here is a specific introduction:
The origin of the name: "75" represents the formula developed in 1975, "8" represents the grade of raw materials used for the tea is around grade 8, and "1" represents Kunming Tea Factory.
Appearance features: usually brick shaped and compact, with a brownish red color, sometimes with a hint of gold, and clear stripes.
Taste and flavor: The taste is mellow and smooth, with a noticeable aftertaste and a distinctive "Xiaguan flavor". The aftertaste is relatively light. New tea has a stronger aroma, while aged tea has a softer and more mellow taste. Dry tea has an aged aroma, and after brewing, it has a unique woody and medicinal fragrance. The soup color is red, thick, and bright.
Status and Characteristics: 7581 is the first label tea in the history of Pu erh ripe tea, known as the "mother of ripe tea". With its stable quality and high cost-effectiveness, it has become a must-have for experienced tea drinkers and new tea enthusiasts.