Why does a gummy bear expand the most in vinegar?

A gummy bear expands in water because of the substance it is made of. The jellylike material is sweet but absorbs water extremely well. Small pockets of air form in the jelly then quickly fill up with water because of its porous design. Hence the expanding jelly bear. Its really cool, so go try it at home! For all of you out there that play minecraft, my username is BuildingFury12.