Casein is the protein that gives melted cheese its oozie stretchiness. It’s present in all milk, and it can appear in processed foods, protein powders, paints and adhesives. Back in the bad old days, many soy cheese companies put casein in their products without disclosing it as a milk ingredient, and few vegans of the time recognized that it wasn’t vegan.
As food technology has advanced, vegan cheese companies have discovered plant-based ingredients that replicate casein’s meltability. There are now several great vegan cheeses on the market that have the same stretchiness as dairy-based cheese.
Casein-Free Vegan Cheese:
Cookbooks for Making Vegan Cheese: