Does cheddar cheese and parmesan cheese need a hechsher?

Kashrut
#1

Are all cheddar cheeses and parmesan cheeses kosher or do they require a hechsher?

#2

Yes all cheddar and parmesan cheeses require a reliable hechsher. This means that a mashgiach must be present when the factory puts in the starters that curdles make the milk into cheese.