OAKLAND, Calif. — You've heard of turning water into wine. But what can you turn wine into once the bottle is past its prime? Plenty say a trio of thrifty chefs who've been turning dregs into delicious vinegars, marinades, even sorbets. "Any good kitchen — waste not, want not," points out Clark Frasier, co-founder of Arrows Restaurant in Ogunquit, Maine. Restaurants end up with wine leftovers for a number of reasons, particularly if they sell a lot of it by the glass, something that's become more popular as consumers have become more cautious about spending. But that trend can leave restaurants with plenty of wine at the bottom of the bottle.