How to Make Homemade Ricotta Cheese Cooking Lessons from The Kitchn. I prefer the recipe from In Jennie's Kitchen, but this one has instructions for making Ricotta Salata and has links to some uses.
Milk, lemon juice, and about half hour of your time — that's all you need to make a batch of fresh, creamy homemade ricotta. You're not going to believe how easy and foolproof this is!
How to Make Homemade Ricotta Cheese: Seems pretty easy: warm milk in pot, when frothy, add lemon juice. let curdle, scoop into cheese cloth & dive, let drip for 60 mins. (Use within a week I think she said).
Homemade Ricotta: gallon whole milk, not UHT pasteurized cup lemon juice (from 1 to 2 lemons), cup distilled white vinegar, or teaspoon citric acid 1 teaspoon salt, optional
All you have to do to make sour cream is stir in a few tablespoons of live yogurt into a cup of cream and let it sit in a warm place overnight! You can also use kefir or extra kefir grains instead of yogurt.