Chowhounds agree: Salting the water you boil your pasta in makes a huge difference to its flavor. As it cooks, the pasta absorbs water, and the salt is incorporated into the pasta with the water, explains Ruth Lafler, who says that adding salt after cooking won’t have the same effect at all. Any kind of salt will do, and it doesn’t make much difference whether you add it before or after the water comes to a boil (though apparently adding it at the start may pit certain types of cookware, warns Nettie). But all agree that it’s important to use plenty of it; several hounds say pasta water should taste “as salty as the sea.”
Board Link: Do you add salt to boiled water for pasta?