What Makes Some Powders Dissolve More Easily?

Two factors: what has been added, and how the powder was processed.

Dextrin

Common on ingredient lists. Made by breaking down starch — potato, corn, tapioca, rice — with acid or enzymes.

Despite the name, it is a food ingredient rather than a food additive.

In powdered drinks it keeps the product free-flowing and prevents caking. It also adds viscosity, prevents separation, and helps freeze-dried products hold their shape.

It does count as carbohydrate, which matters if you track that.

Emulsifiers

Help water and fat combine. They appear in products formulated to be mixed with milk.

Granulation

Processing matters as much as composition.

Fine powder has enormous surface area. Pour liquid on and the outer surface wets, forming a barrier that keeps the interior dry — this is where lumps come from.

Compressing powder into small granules lets water penetrate the interior. Instant coffee comes as granules rather than fine powder for exactly this reason.

Matcha does not dissolve regardless

Worth stating plainly: matcha never dissolves.

Ground leaf particles disperse through the liquid and stay suspended. Left standing, they settle. Only the sugar portion genuinely dissolves.

So no product will ever go completely clear, and a little residue at the bottom of a cup is inherent to drinking ground leaf.

Products without these aids

Some contain only matcha and sugar, with nothing to assist dispersion. They clump more readily.

The fix is technique rather than chemistry: work the powder into a paste with a small amount of liquid, then add the rest. Agitate with a whisk or shaker. For cold drinks, dissolve in a little hot water before adding ice.