I have not made this yet but have a question.
Maybe there is an obvious answer to this when making the recipe, but should the caramel be stored in the refrigerator overnight? If so would it then need to be heated or at room temperature before pouring it over the custard?

No, the caramel cannot be stored separately overnight. It is poured into the ramekins and the custard is then poured over that. The dessert is left to set in the refrigerator. Once it has chilled long enough, the whole dish is unmolded together. Cheers!

Thanks Kimberly, from the picture it looks as though it was added afterward also. It must spread after being refrigerated.
I appreciate the response.

What purpose does scalding the milk serve in this recipe?

In this case, we are just saying to heat the milk to just before the boiling point (you should see small bubbles around the sides of the pot). The hot milk will ensure that the sugar gets fully dissolved into the custard base. Cheers!

My caramel was too hard to be easly poured. A lot of it remained stuck to the pan. What I did wrong?

Pas de probleme, simply put back the pot with caramel on the stove to melt it back until it is ""pourable"'. Bonne chance.

Hi. I repeated this recipe four times trying to control the heat and the cooking time. But I couldn't avoid getting a skin on the surface of the cooked custard in all the trials, even for a relatively undercooked custard. How can I solve this? Thanks in advance.

I'm not entirely clear at what point in the process you are getting a skin on the surface. If you are referring to a skin that may occur after baking, next time you can loosely cover the baking pan with foil... but not too tight - this can cause the water to come to a boil and any steam that is trapped can also fall into the custards and water them down. Also, make sure your oven isn't running too hot. Custards love gentle heat, so feel free to also reduce the temperature by 25-50 degrees. Hope this helps. Cheers!