Rennet is the essential enzyme used to coagulate milk into curds. It is most commonly found in these locations: Where to Buy Rennet for Cheesemaking - The Spruce Eats
Finding rennet and citric acid locally can be a bit of a treasure hunt, as they are often tucked away in non-obvious sections of the store. Generally, offer the widest selection and best value, while physical stores are your best bet for immediate, small-scale needs. Where to Buy Rennet where to buy rennet and citric acid