Añejo is a firm, Mexican cheese. It is actually the cheese called “queso fresco” (which is usually made from both cow and goat milk) that has been allowed to age. As it ages, it becomes solid, dry, salty and crumbly, almost like Romano or Parmesan, though it remains more white than they do, looking somewhat like feta cheese. It is used as you would Romano or Parmesan, crumbled, grated or shredded over foods or mixed into them.
Because this starts life as a soft cheese it is often classified as a soft cheese; you may encounter it in varying stages of hardness from semi-firm to hard depending on how long it has been aged. Consequently, you will see varying directions for either “grating” or “shredding” it.
Like most Mexican cheeses, this would have been completely impossible to find in North American food stores a few years ago, but with the rising Hispanic population in America, the chance of finding it without heading to ethnic markets can now be said to be upgraded from completely impossible to just highly unlikely (2004.)
Some suggest unhelpfully that you could substitute Mexican Cotija cheese (which has a stronger flavour, is harder and more crumbly), but any place that you schlep to looking for cotija is probably also going to sell Añejo.
Some people, (dismissing the obvious easy substitutes of Romano or Parmesan because the taste isn’t the same as añejo), try mixing washed, dried feta with grated Romano, though they lament that the flavour is still not the same.
Since the flavour’s going to be different anyway, just use Romano or Parmesan; you think the Mexicans don’t make substitutes when making our recipes?
Literature & Lore
“Queso” in Spanish means cheese; “Añejo” means aged.