The phrase "cheese rind" refers to the outer layer of a cheese. It is the part that develops as the cheese ages and helps protect the softer inside. Full definition
I think I would add a Parmesan cheese rind in while the soup cooks for added flavour. (recipegirl.com)
Professor Rachel Dutton, along with postdoctoral researchers Ben Wolfe and Julie Button, has spent the past several years mapping, analyzing and otherwise fiddling with the microbial communities in 160 different kinds of cheese rind. (canadianbusiness.com)