What is Buttermilk? And How to Use it for Cooking. | Eater

"A family-run dairy in Knoxville, Tennessee, led by co-owner Colleen Cruze Bhatti, produces a hybrid-style buttermilk made by agitating cultured milk and cream together so the process yields both butter and buttermilk. The co-owner describes the product as “a drinkable yogurt” and a cousin to yogurt and kefir, resulting in a creamier, hybrid texture that combines qualities of true buttermilk and cultured whole-milk varieties and works well for baking, dressings, and other recipes that benefit from both tang and emulsifying richness." - Nick Mancall-Bitel