Queijo da Ilha
Also known as: Azores cheese, Ilha cheese
A semi-hard cow's-milk cheese from São Jorge island in the Azores ("queijo da ilha" translates to "cheese of the island"), aged until it develops a sharp, tangy, slightly spicy flavor somewhere between a sharp cheddar and an aged provolone. Melts well, making it a common choice both grated over dishes and eaten on its own.
Buying guidance
Look for it at a Portuguese grocery store or a well-stocked specialty cheese counter -- it's not a supermarket staple outside areas with a Portuguese community. Aged versions are sharper and more crumbly; younger ones are milder and melt more smoothly, which matters if it's going into a filling meant to stay creamy.
Substitutions
- Provolone -- a widely available substitute with a similar sharp, tangy melt.
- Aged sharp cheddar -- shares the tang and meltability, though the flavor is distinctly different (cheddar rather than Portuguese-style).
- Fontina or mozzarella -- milder and creamier, gives up some of Queijo da Ilha's characteristic tang in exchange for easier availability.
Tips & common mistakes
Because it's less commonly stocked, it's easy to buy a much younger or much older wheel than intended without realizing how differently they behave -- a well-aged piece is noticeably sharper and firmer than a younger one, so taste a small piece before committing a whole block to a recipe if the age isn't marked.
Storage
Wrap tightly in wax or parchment paper (not plastic, which traps moisture and encourages mold) and refrigerate; it keeps for several weeks this way, and firms up further -- getting sharper -- the longer it's kept.