Catalysis of the reaction: a 1,2-diacyl-3-O-(beta-D-galactosyl)-sn-glycerol + 2 H2O = 3-beta-D-galactosyl-sn-glycerol + 2 a fatty acid + 2 H+.
1,2-diacyl-3-beta-D-galactosyl-sn-glycerol acylhydrolase activity