Cheddar cheese lasts about three or four weeks in the refrigerator when it is in a block and already opened. If properly wrapper, an opened block of cheddar cheese can last up to six months in the freezer.
It is best to wrap the block of cheese in parchment paper or wax paper to store it, and then wrap it in plastic wrap. Cheddar cheese must always be stored in the refrigerator or freezer to keep it fresh. If freezing cheddar cheese, cut it into smaller chunks, then wrap it in plastic wrap, followed by placing it in a freezer-friendly bag or container. Frozen cheddar cheese is slightly crumbly after thawing.