01 -
Put your heavy cream into a clean container that won't react with it.
02 -
Mix in the yogurt or buttermilk with the cream.
03 -
Give it a gentle stir to blend everything together.
04 -
Loosely cover the container with its lid.
05 -
Leave it sitting at room temperature for roughly 12 hours.
06 -
When it feels like sour cream to touch, it's thick enough.
07 -
Pop it into the fridge when it's reached the right consistency.