A year of dairy experiments — what I learned

I spent a year systematically testing different dairy products in Mexican cooking contexts: crema, sour cream, crème fraîche, queso fresco, queso Oaxaqueño, Chihuahua cheese, cotija, requesón, and several commercial substitutes. Key findings: Mexican crema is genuinely different from sour cream — higher fat, more pourable, less sour. Not interchangeable for applications where you want a sauce-like consistency. Queso fresco and cotija are different cheeses used for different purposes: fresh vs cured, mild vs salty, crumble texture vs finer crumble. Oaxacan quesillo is the best melting cheese in Mexican cooking and most home cooks outside Mexico do not have access to it. Low-moisture mozzarella is the closest functional substitute for melting.