What you need:
2 large bowls
1 mesh strainer that fits over the bowl
1 spatula
Cheese cloth
Directions:
First, you want to make sure your kitchen tools are very clean to prevent the introduction of unwanted bacteria.
Pour the milk into the first bowl & cover with the cheese cloth, securing it with kitchen twine or rubber bands. This makes sure foreign objects & even critters don't get in.
Use fresh or sour milk to make this, but fresh takes a lot longer. The batch shown, was mad with a half gallon of fresh milk & a half gallon of curdled sour milk.
Let the gallon of milk sit out away from heat sources such, as the stove or microwave until it becomes gelled, like a yogurt consistency. (This batch took a week to get there).
Check every 12 -24 hours to see if there is anycream to skim off. This would be your sour cream (I didn't get enough to skim)
Once the milk is like a lumpy yogurt consistency (check be shaking the bowl), strain into the second large bowl. Cover bowl while straining, as this step will take a few hours. At the end of this step, the only thing left in the strainer should be curds, & all the whey should be in the bowl underneath. (Mine took 24 hours to strain)
Now scoop the curd out with, a spatula, careful not to smear it too much & break it up.
The leftover liquid in the bowl is whey. It can be frozen & used for many things.
Total time for mine took was 9 days, & my family gave me grief for it for the last 5 days of it.