"It is very American to want cheese alternatives to be identical [to eating regular cheese]," says food scientist and nutritionist Kristi Crowe, a spokesperson for the Institute of Food Technologists and assistant professor at the University of Alabama.

How to do this has been stumping scientists for years. Dairy cheeses and even some lactose-free varieties rely on a milk protein called casein. Casein is "a truly remarkable protein like nothing else on the planet, and it allows real cheese to melt and stretch,"says Jonathan Gordon, a food scientist who earned his Ph.D. by studying the fermentation of soymilk for use in food products. Gordon has done stints at Kraft and now a company called Galaxy Nutritional Foods to try to perfect the cheese-like experience.

"It's sort of analogous to a zipper that doesn't have an end on it," Gordon tells The Salt. "The casein protein has an ability to hold onto itself and then lightly let go and then hold onto itself, and that's how it stretches."

But to make a true vegan cheese substitute, you can't use casein. So Gordon's latest challenge has been to make a cheese that is completely free of animal byproducts but still retains the properties we love about cheese.

"The skill of the formulator is to use exactly the right amounts and blend of gums, protein, solids and fats to get a desirable, cheese-like bite and mouth feel while achieving a realistic melt (this is very difficult)," he tells The Salt.

Those gums replace the casein, working as "emulsifiers" and "stabilizers" to hold the other ingredients together, according to Crowe. (The other ingredients include a protein base like soy or rice, water, oil, starches, flavors and colors.)

Emulsifiers like amino acids actively hold water-rich and fat-rich ingredients together. Stabilizers like carrageenan and xanthan gum, "act as a wall in between the [water-based and oil-based ingredients] to keep the two from mixing," Crowe says.