It's famously sealed with red wax

EDAM

This Dutch cheese is often recognized by its round shape and is coated in a distinctive red paraffin layer to preserve freshness.

The clue plays on Edam cheese, which is traditionally covered in a red wax coating to preserve it. The phrase "sealed with red wax" hints at this distinctive feature, making it a clever nod to the cheese’s packaging. It’s a straightforward reference rather than a pun, relying on the well-known visual trait of Edam.