Susan Kress, age 16, of Louisville, Kentucky, for her question:

How are cheeses given different flavors?

Blue cheese may get its tangy taste from tiny molds called Penicillium roqueforti. The flavor and texture of Camembert cheese is assured by inoculating the milk with cultures of two spores. One is Penisillum camemberti, the other Oidium lactis. As these moldy midgets thrive and multiply, they destroy the milk's lactic acid and attack the caseins in the liquid. Some cheeses get their unique flavors from bacteria. The refreshing taste of Swiss cheese is created by Propionibacterium heleveticum    which also creates those impossible round holes.

Our wonderful variety of tasty cheeses originated in different parts of the world. They occurred by accident, in places where this or that mold or bacterium happened to be plentiful. Nowadays, the cheese making strains have been isolated and identified. They are prepared in pure cultures and added to the milk. The mixtures are given time to cure, while the helpful midgets change them into cheese.