Scalding is a step below boiling — it's somewhere around 190F for a mixture of heavy cream and milk. Signs to look for: A skin forming on top of the cream, steam coming off the top of the mixture, tiny bubbles around the edges of the pot. And the final sign: If you tip the pot forward slightly, you should see lots and lots of active bubbles on the bottom of the pot. Don't feel like you need to rush once your heavy cream and milk have scalded. Turn the heat off, remove the cardamom pods, and then proceed to the tempering step.