Particle size, and why it decides everything

Particle size is the property most suppliers mention least and the one that determines whether a blend stays a blend.

The variable underneath the others

It sets bulk density, and therefore what a scoop delivers. It sets flow, and therefore how the powder fills and dispenses. It sets dissolution, and therefore whether it lumps in a shaker. And it drives segregation, which is whether the blend survives being handled.

Four downstream problems, one upstream variable.

The spread matters more than the average

Two blends can share a mean particle size and behave completely differently. What causes trouble is the range.

Components differing in size, density, shape or surface properties separate once allowed to move relative to each other, and a wide distribution guarantees there are small particles available to percolate down between large ones.

Powders of similar size and density blend more uniformly and are less likely to separate. That one sentence is the entire design rule for a supplement blend.

What it drives

Segregation, most importantly, because in this category a separated blend is a potency problem rather than an aesthetic one.

Flow and dosing, since a fine cohesive powder does not flow and a coarse free-flowing one packs differently in a scoop.

Solubility, since very fine particles clump on contact with water rather than dispersing, which is the lump in the shaker bottle.

Segregation during filling as well as in the tub, which means a run can drift from first unit to last.

Specifying it

Ask suppliers for the mesh or micron specification rather than accepting a description. Where components differ widely, the fix is upstream: choose grades that are closer to each other rather than blending harder.

Write it into your component specifications, because it is the attribute that changes silently when a supplier reformulates or a new lot arrives, and it is the one that will show up months later as an inconsistent product.

References