Pour the milk into a large jar, leaving some space at the top as it will expand while souring. Seal the jar and place it in a warm spot, out of direct sunlight. In a cooler kitchen, this can take up to 48 hours to thicken and separate.
Once ready, the milk will be thick with a yogurt-like consistency, and the whey will have separated from the curds, appearing clear and slightly yellow. The cream will rise to the top. Your soured milk is now ready.
Line a colander with cheesecloth and place it over a large bowl or pot. Slowly pour in the soured milk, being gentle to keep the curds large. Let it drain for several hours, or overnight if needed. The longer it drains, the drier your cottage cheese will be.
After 30–60 minutes, you can gently tip the colander from side to side or gather the cheesecloth to help release more whey.
If the cheese is still too runny, you can tie up the cheesecloth and hang it to drain further. This step is optional and depends on your desired texture.
Once thick and creamy, transfer the cheese to a bowl. Stir in about 1/2 teaspoon of unrefined salt, then taste and adjust. Salting is optional but enhances flavor and helps preserve the cheese. Skip the salt if you plan to use it in sweet dishes.
Place your homemade cottage cheese in the fridge to chill before serving. If you plan to use it in a recipe right away, chilling is not necessary.