I have a recipe that calls for melting margarine, adding brown sugar, and boiling a few minutes before pouring it over matzah boards. The problem is that the margarine separates, and the brown sugar never totally dissolves.
I assume we are making candy or fudge. Heat the brown sugar first when you have it to temperature, stir in the margarine off the heat then pour it.
I just had the problem 2 batches in a row. The 3rd time, I made sure that the margarine was at room temp (not directly from the fridge). I then started heating at a low temp instead of medium so that it heated more slowly. This batch worked perfectly