Beta-glycosidase that catalyzes the transfer of glucose moiety to anthocyanidin 3-glucoside at the 5 position. Anthocyanins are ubiquitous colored pigments that are responsible for variations in petal color. Uses acyl-glucoses, but not UDP-glucose, as the glucose donor. 1-O-(trans-sinapoyl)-beta-D-glucose + cyanidin 3-O-beta-D-glucoside = cyanidin 3,5-di-O-beta-D-glucoside + E-sinapate kcat is 0.06 sec(-1) with cyanidin 3-glucopyranoside (with native enzyme at pH 5.0 and 30 degrees Celsius). kcat is 0.01 sec(-1) with 1-O-beta-D-vanillyl-glucose (with native enzyme at pH 5.0 and 30 degrees Celsius). kcat is 0.07 sec(-1) with cyanidin 3-glucopyranoside (with recombinant enzyme at pH 5.0 and 30 degrees Celsius). kcat is 0.01 sec(-1) with 1-O-beta-D-vanillyl-glucose (with recombinant enzyme at pH 5.0 and 30 degrees Celsius). Optimum pH is 4.5-5.0. Optimum temperature is 48 degrees Celsius. Pigment biosynthesis; anthocyanin biosynthesis. Expressed in petals. Expression peaks at stage 2 of petal development. Petal color variations. Petals accumulate anthocyanin lacking the glucosyl moiety at the 5 position. Belongs to the glycosyl hydrolase 1 family.