Refining

Reducing the particle size below the threshold at which the tongue can detect grain — roughly 20 to 30 microns.

Step 30 of 43At the factory

Chocolate contains solid particles — cocoa solids, sugar crystals, milk powder — suspended in fat. Human perception of grittiness has a threshold somewhere around 25 to 30 microns, and refining exists to get every particle below it.

That is the whole objective, and it explains a common confusion: refining is about texture, not flavour. A chocolate refined to 40 microns tastes gritty regardless of how good the beans were, and Mexican stone-ground drinking chocolate is deliberately left coarse because the grain is characteristic of the product.

What it does

Reduces solid particle size, typically to under 30 microns, so that the tongue perceives the chocolate as smooth.

Why it matters

Below the perception threshold, chocolate reads as smooth; above it, as gritty or sandy. There is no flavour compensation for a coarse refine.

When it goes wrong

Under-refining, which gives a sandy or chalky mouthfeel. It is the most common single flaw in small-batch chocolate, because adequate refining takes considerably longer than it appears to.

Commonly misunderstood

That refining and conching are the same step. They overlap in a melangeur, which does both at once, but they do different things: refining reduces particle size, conching drives off volatiles and coats particles in fat.

Related

Flavour developed here

  • ChalkyThis stage is where the note is created, amplified or destroyed. A gritty, sandy texture rather than a flavour. Under-refining, and the most common flaw in small-batch chocolate.

Defines

  • Craft chocolateReducing the particle size below the threshold at which the tongue can detect grain — roughly 20 to 30 microns.

Commonly confused with

  • ConchingThey happen together in a melangeur and do different things: refining reduces particle size, conching removes volatiles.

Required by

  • Dark chocolateParticle size below the perception threshold is what separates modern chocolate from stone-ground drinking chocolate.
  • Milk chocolateMilk powder adds another solid to keep below the perception threshold, which is why milk chocolate refining is its own problem.

Covered in

History and culture

Sources

  • ChocolateHQ editorial synthesisChocolateHQ(citation identity confirmed; passage not re-read)
  • The Science of ChocolateRoyal Society of Chemistry(citation identity confirmed; passage not re-read)