Why does sour cream curdle when baked in a layered gratin?

I used in a sweet potato gratin. Layers were sweet potatoe, sour cream, spices sprinkled on cream, then cheese layer. You do this for 3 layers and bake at 400 for 40 minutes. It was tasty, but sour cream curdled and looked terrible. How could this be done without this problem? Thanks.Why does sour cream curdle when baked in a layered gratin?
The curdling or splitting of fat from whey happens due to the heat, my suggestion is to use a higher fat sour cream and make a bechamel sauce white cream sauces as base 1oz. butter, 2oz. flour, 3oz. milk, fold in your sour cream and the bechamel sauce will stabilize your cream and stay solid in your gratinWhy does sour cream curdle when baked in a layered gratin?
I agree