Grating cheese can be frustrating when working with soft varieties like mozzarella. To prevent a mushy mess, put the cheese in the freezer for 15 to 30 minutes.
When cheese is cold, its fat content solidifies, giving it a firmer and more stable structure. This makes it much easier to grate without turning into a gooey mess.
Additionally, giving your grater a quick spritz with cooking oil before you start grating will help the cheese effortlessly glide through the grater without sticking.