Mesh and particle size

Particle size is the specification most small producers never set, and it quietly decides how a blend behaves, how a jar looks, how the sifter performs and how fast the flavor goes.

What mesh means

Mesh is the number of openings per linear inch in the screen the material passes. Higher mesh is a finer powder. Industrial cryogenic mills are built to produce 80 mesh or finer, and can be set to around 50 microns. A domestic grinder produces something much coarser and much less uniform, which is not automatically worse.

The range matters more than the average

Two batches can share a mean particle size and behave completely differently, because what causes trouble is the spread. A wide particle size distribution is the direct cause of segregation later: small particles filter down between large ones every time the container is moved.

So a consistent medium grind is more useful than an inconsistent fine one. If you are buying a mill, uniformity is the specification to care about, not fineness.

What a fine grind costs

Surface area. A finer powder exposes more of itself to air, so it loses volatile oil faster and oxidizes faster. It also packs denser, which makes the jar look better and the same weight occupy less space, and it cakes more readily because there are more contact points for a liquid bridge to form across.

Fine is not a quality grade. It is a set of trade-offs, and most of them are against you.

Choosing a grind

Match it to use. Something going into a shaker wants coarse enough to flow and fine enough to pass the apertures. Something going into a rub wants to coat, so medium. A blend wants every component within a narrow band of each other, which matters far more than where that band sits.

Write the grind down as part of the product specification, the same way you would write the weight. It is the attribute you will otherwise change by accident when you replace a mill.

References