How do I fix and prevent a baked custard from weeping? I made a rhubarb custard pie that turned out  nicely; the custard was flavored with orange zest and 2 tablespoons of orange juice and 1 teaspoon of orange flower water. 

I wanted a baked custard made of the filling without the crust.

I doubled the recipe and baked it in a souffle dish, using a water bath under the souffle dish. I baked it at 325F. It took almost 2 hours for the knife inserted in the center to come clean.

The custard was a  good texture when removed from the oven and cooled, but when I scooped some out, clear sugar fluid accumulated  where I scooped.

The fluid tasted only of sugar, not the rhubarb or the orange flavors.

I tilted the souffle dish. Overnight approximately 2/3 cup of fluid accumulated in the space where I had scooped .

My question :

Why did this happen?

What could I do to avoid it happening in the future?
Why did this happen?


One possibility is that the outside of the custard became overcooked while you were waiting for the middle to set. As eggs cook longer they tighten up more and more, squeezing out liquids that were previously captured by the protein matrix. The cooking process continues for a while even after you remove the custard from the oven, so the overcooking might have happened later than you'd think.


  What could I do to avoid it happening in the future?


If the overcooking hypothesis is correct, then any of the following could help:


Reduce the cooking time. Most custard recipes that I can think of call for cooking times around an hour, depending on the size of the dish.
Use smaller baking dishes. With a smaller dish, you won't have to wait as long for the center to set.
Use a shallower baking dish. Same as above -- cooking the custard in a thinner layer should help the whole thing set more quickly.
Remove from oven before it's completely done. With some recipes, like cheesecake, you need to remove the item from the oven before it seems to be done. This prevents overcooking at the edges and cracking in the middle. The same idea could work for your custard.
Modify the matrix. Many custards contain ingredients like starch or gelatin, which can fortify the protein matrix that gives the custard body.