Pour the cream into a heavy-bottomed oven-safe pot. The cream should come up the side of the pot somewhere between one and three inches.
Cover the pot and put it in the oven on 180 F.
Leave the covered pot in the oven for at least 8 hours. My four cups took 12 hours (until my oven automatically turned off). You'll know it's done because there will be a thick yellowish skin above the cream, as shown above. That skin is the clotted cream.
Let the pot cool at room temperature, then put it in the refrigerator for another 8 hours.
Skim and reserve the clotted cream from the top of the pot. (The milky liquid underneath is great for coffee and tea, but won't work well for most baking applications as the fat has been skimmed off as part of clotted cream.)
Notes
To make clotted cream in a rice cooker, make sure that your model has a keep warm setting that keeps the liquid above 140 F. The
Add four cups of heavy whipping cream to your rice cooker bowl and place into your rice cooker.
Set the rice cooker to keep warm and leave, covered, on the keep warm setting for 12 hours. Check periodically to make sure that your rice cooker hasn't shut off.
Remove the bowl, allow to cool to room temperature, and refrigerate for 8 hours.
Using a slotted spoon, skim the yellowish surface of the liquid off and store in a jar in a refrigerator.
Using a pot or a rice cooker yields 1.5 cups of clotted cream from 4 cups of heavy whipping cream.Clotted cream can be stored in the refrigerator for 3-4 days. Because of its high fat content, clotted cream can also be frozen for longer storage.