system
Given the following post, respond as if you're commenting on Reddit:
human
Hot Chocolate?

So here is a question that I have been wondering. What has better distribution? Pouring a hot liquid on the hot chocolate mix. Or, Pouring the hot chocolate mix into the hot liquid. 

Follow up question, which liquid distributes the hot chocolate mix better, water or milk?
gpt
Water is hydrophilic, milk is a mostly water emulsion with some fats giving it some hydrophobic character. Without knowing every last compound in he mix which can vary, it would be speculation to say. Given that theres chocolate which has dairy fats milk would be more reasonable choice. 

You have a greater chance of powder clumping if you were to dump the powder on top of the liquid. If you were going to prepare it like a chemist who can't leave procedure in the lab, you would add the liquid to the solid. You would add a small amount of liquid and mix, just enough to make a slurry ( a loose paste consistancy ) then bring it up the desired liquid level. 

Dumping powder into the liquid or quickly adding liquid to the powder can cause clumping. The two different mediums flow differently and Van der Waals forces come into play. While there are some powders that you would swear look liquid when poured, most don't. Powder particles are still solid and exhibit more friction upon each other than a liquid. If the liquid is allowed to surround an amount of powder instead of solvating , the water will then be pushing on this clump of powder from all sides. It is still solvating, but only on the surface area of the clump.