To make cream cheese, producers start with fresh pasteurized cream or a
combination of milk and cream, then add lactic acid bacteria to lower the
pH, which causes curds to form. The whey gets drained, the curds get
heated, and added stabilizers provide structure. Cream cheese is meant to
be eaten fresh and does not require aging.
You can make cream cheese at home by adding salt and an acid such as lemon
juice or vinegar to cream or milk, then straining the resulting curds and
pureeing them in a food processor or blender until smooth.