Why chocolate is grainy
Four different causes produce the same sensation, and only one of them is anything to do with the chocolate being badly made.
If you read nothing else
Grain through a whole bar is refining; grain on the surface only is sugar bloom; grain that appeared in your bowl is seizing or scorching. Break a piece to tell which.
Under-refining
The manufacturing cause. Human oral texture perception detects particles down to about 25–30 microns; below that a suspension reads as smooth. Well-refined chocolate runs around 18–20 microns.
A craft bar from a small melangeur operation occasionally sits above the line, and traditional stone-ground Mexican drinking chocolate sits far above it by design. In the second case the grain is characteristic rather than a fault.
Sugar bloom
The storage cause, and the one most often mistaken for the first. Moisture on the surface — usually condensation from a fridge — dissolves surface sugar, which recrystallises as a rough gritty layer when the water evaporates.
It feels like poor refining and is not. The tell is that it is on the surface only: a piece broken open is smooth inside.
Seizing and scorching
Two kitchen causes. Seized chocolate is grainy because sugar particles have clumped; scorched chocolate is grainy because sugars have caramelised and milk solids have burnt.
Seizing is recoverable into a sauce. Scorching is not recoverable at all, and it comes with a cooked smell that distinguishes it.
Telling them apart
Break a piece. Grain that runs all the way through an unopened bar is refining. Grain confined to the surface is sugar bloom. Grain that appeared in your own bowl during melting is seizing if it was sudden and stiff, and scorching if it came with a burnt smell and a dull colour.
Only the first is a judgement on the maker, and even then it may be deliberate.
Covered in this guide
- Particle size controlThe manufacturing stage that determines whether a bar is smooth.
- ChalkyThe sensory descriptor, and how it is used in tasting notes.
- Chocolate has bloomedWhat to do when the cause is bloom rather than refining.
Sources
- ChocolateHQ editorial synthesis — ChocolateHQ(citation identity confirmed; passage not re-read)
- The Science of Chocolate — Royal Society of Chemistry(citation identity confirmed; passage not re-read)