Provided is a non-tea-based, packaged beverage which includes a sour seasoning, contains catechins at high concentration, and even after stored over along term, can still give a refreshing feeling specific to a sour taste. The non-tea-based, packaged beverage is free of the persistence of a sour taste, which is experienced when taken in sport scenes, and is excellent in mouth refreshment. Even in a form filled in an oxygen-permeable, clear container, the non-tea-based, packaged beverage shows excellent color tone stability. The non-tea-based, packaged beverage contains a purified product of green tea extract added to it. The purified product comprises non-polymer catechins in its solid constituents and has a content weight ratio of (B) oxalic acid to (A) the non-polymer catechins [(B)/(A)] in a range of from 0 to 0.002. The non-tea-based, packaged beverage comprises the following ingredients (A) to (D): (A) from 0.03 to 0.6 wt % of non-polymer catechins, (B) oxalic acid or a salt thereof at an ingredient (B)/ingredient (A) of from 0 to 0.02, (C) caffeine at an ingredient (C)/ingredient (A) weight ratio of from 0 to 0.16, and (D) from 0.03 to 1.0 wt % of a sour seasoning, and has a pH of from 2 to 6.