The best cheese is not always the strongest or most expensive. It should fit the temperature, filling and amount of other richness in the sandwich.
For clean melting
American-style cheese melts evenly and stays creamy. Young cheddar, Monterey Jack, mozzarella, provolone and fontina also melt well when sliced thinly and heated gently. Very aged cheeses may separate or remain oily rather than forming a smooth layer.
For sharp flavor
A small amount of aged cheddar, blue cheese, feta or sharp provolone can season an otherwise mild filling. Use restraint when the meat, pickles or sauce are already salty. Crumbled cheese needs a spread or moist filling to keep it in place.
For creaminess and spread
Fresh cheese, cream cheese, ricotta blends and soft goat cheese can act as both flavor and moisture barrier. They pair well with vegetables, smoked fish and fruit-forward condiments. Spread to the edges in a thin layer rather than creating a thick central patch.
Placement for hot sandwiches
Put cheese near the hot filling or near the pan so it receives enough heat. In a grilled cheese, combine a good-melting cheese with a smaller amount of a stronger cheese. Covering the pan briefly can help the centre melt before the bread over-browns.
Placement for cold sandwiches
Cheese slices next to bread can protect it from wet fillings. However, two smooth slices around tomato can create a slippery plane. Add lettuce, folded meat or textured spread for friction.