Why does powdered coffee creamer dissolve easily in fresh, hot coffee but not reheated, hot coffee?

Question

I’m new to using powdered coffee creamer, but I’ve noticed that, with a spoon to stir, it mixes instantly with a fresh pot of coffee but 30 minutes or an hour when I go to pour the second cup, it clumps up and can’t be mixed. Same result when I keep the pot heated and/or when I reheat the mug in a microwave.

In: 9

Answer 1

Something that also makes a difference is whether you add the coffee to the cup with creamer already at the bottom (which is what I tend to do with fresh coffee) or add creamer on top of the coffee (what I tend to do with reheated coffee). The first is usually enough to mix it all on its own without needing a spoon.