Glucan endo-1,3-β-D-glucosidases are enzymes that cleave internal linkages in beta-1,3-glucans such as laminarin and yeast cell-wall glucans. Brewers use related beta-glucanases to break down viscous barley glucans that cause filtration problems and haze, while in baking they modify dough structure and in brewing yeast management they aid cell-wall breakdown. Their specificity for beta linkages distinguishes them from starch-acting amylases, so they target cell-wall and storage glucans without attacking starch. Commercial preparations are standardised for activity and used at low doses to improve processability and clarity.