Whenever I make a sauce that includes cream, the cream separates. I used to be able to make these sauces perfectly but lately they keep failing. I don't know what I am doing differently. Does anyone know what I am doing wrong?
Depending on what sauce you're making, quantities, temperatures and timing all varies, so it's a little difficult to say exactly where you might be coming unstuck. But there are a couple of things that might be causing your sauce to separate:
1. Incorporating oil or butter into your sauce too quickly (you want to do this slowly and methodically)
2. Heating your sauce to quickly (don't let it boil)
3. Not whisking briskly enough
4. Leaving the sauce too long before serving
With any sauce like this, the challenge is that oil and water don't really mix, so you need an emulsifying agent to bind the two together — usually egg, cream, milk or sometimes flour. In your case, it's cream. When you add your emulsifier too quickly or whisk too slowly, it doesn't do the job it needs to do. Too much heat cause similar problems.
We do have an online course, "Success With Sauces" that covers techniques, tips and troubleshooting.