Don't know if I'd quite call myself a full-fledged pastry chef, but I do make the dessert menu for one of the restaurants I work at. So I apologize if this is in the wrong forum - seemed like the right place for my question.
We make ours by doing a zabaglione with marsala wine. I temper in the mascarpone, and then fold in beaten egg whites. I just line the walls of coffee cups with soaked savoiardi, add the custard on top, and let it set up overnight. I've noticed that the bottoms of the lady fingers become much too wet after sitting overnight, and I suspect it may be the custard breaking a little.
It's not the zabaglione failing. I've made that mistake before, and the result is a very noticeable layer of liquid at the bottom of the mug.
Now I'm wondering if this is because we use egg whites. I was thinking cream of tartar may help this issue as I've read it stabilizes an egg white foam.
What are your thoughts? Would I be straying from tradition with COT?