While nature cheese is made from all-natural ingredients and ripened, processed cheese is usually made partially from natural cheese with preservatives and artificial ingredients added. Processed cheese is then emulsified and pressed in shaping for slicing or extruded into cans and jars. Processed cheese also generally has a much higher sodium content that natural cheese, and unlike natural cheese, it’s usually shelf-stable.
Most natural cheeses are made from very simple ingredients – milk, rennet (enzymes produced in the stomachs of ruminants) and salt. Natural cheese flavors and textures derive mostly from different kinds of milk and rennet. After the whey is drained away from the curds, it’s formed into wheels and aged (from 60 days to three years in some cases) to achieve the correct flavor.
While processed cheeses do contain some natural cheese, they also contain whey, cheese culture and other additives such as sodium citrate, sodium phosphate and sorbic acid. Also, unlike many natural cheeses, much processed cheese contains annatto to color it orange. Most processed cheese has been designed for long shelf life, so once it’s emulsified and blended, it can be packaged and shipped immediately. Although it’s more convenient in some ways than natural cheese, processed cheese is also usually more expensive than common varieties such as cheddar and Swiss.