What are the two reasons of baking egg custard in bain-marie?

1. Even cooking: Baking an egg custard in a water bath (bain-marie) ensures even cooking. The hot water surrounds the custard dish, transferring heat gently and uniformly to the entire custard. This prevents the custard from overcooking or developing hot spots, resulting in a smooth and creamy texture.

2. Prevention of curdling: Egg custards are susceptible to curdling due to the high protein content in eggs. When exposed to high heat, the proteins can coagulate and form lumps. By baking the custard in a bain-marie, the temperature is regulated, preventing sudden changes that could cause curdling. The gentle heat from the water bath allows the custard to cook slowly and evenly, minimizing the risk of curdling.