Pronounced CAH-cheeoh, cacio is a synonym for il formaggio: both words mean cheese in Italian, both cacio and formaggio are masculine singular nouns, and both can be used as uncountable or countable nouns. The plural of il cacio is i caci, which corresponds to cheeses.
In terms of the type of cheese the words refer to, there’s no difference between cacio and formaggio. Cacio does, however, have a different root than formaggio.
Il cacio comes from the Latin word caseus, which is usually translated simply as cheese. Many people believe the ancient Romans actually borrowed caseus from Celtic or Germanic sources, as you can read in this interesting discussion. The term formaggio, however, is widely believed to come from the Latin root formaticum or caseus formaticus, which mean shaped or shaped curd, respectively.
So when do you use the term cacio and when do you use the term formaggio?
- If you’re talking about dressing your pasta with cheese and pepper, use the expression cacio e pepe.
- If you want a super-cheesy pizza, ask for pizza ai quattro formaggi [4 cheese pizza].
In most other occasions, there are no hard and fast rules. Cacio is more familiar term, while formaggio is more general. You might opt to use cacio when referring to local cheese, and formaggio when talking about cheese from other regions or outside of Italy.
The further South you go in Italy, the more likely you are to hear people using the term cacio. But rest assured that anywhere you go in Italy, both words will work!
If this is the kind of learning you like to do, pick up a copy of Italian Through Food!