Winnowing

Cracking the beans and separating the shell from the nib by air. Mechanical, not chemical.

Step 25 of 43At the factory

A cutaway of a dried cacao bean. A thin outer shell, labelled as about twelve per cent of the weight, encloses a dark folded cotyledon labelled as about eighty-seven per cent — the nib that becomes chocolate. A small germ sits at one end, labelled as about one per cent. — Inside a dried cacao bean. Proportions are approximate and vary with origin and bean size; the drawing is schematic rather than to scale. Generated from ChocolateHQ’s own records rather than drawn or photographed.

The roasted bean is cracked and the fragments passed through moving air. The shell is light and blows away; the denser nib falls. What remains is nib — the part that becomes chocolate — at around fifty per cent cocoa butter by weight.

Nothing about flavour happens here, but shell left in the nib is gritty, dilutes the chocolate and carries a fibrous off-taste, so the efficiency of the separation is a real quality variable and is one of the hardest things for a small maker to do well.

What it does

Cracks the bean and separates the lighter shell from the denser nib using airflow.

Why it matters

Residual shell is gritty and tastes woody, and it does not grind out. Small-scale winnowing is inefficient, which is one of the practical limits on very small production.

Optional?: Not optional for solid chocolate. Cocoa shell is separately used for tea-like infusions.

When it goes wrong

Shell carried through into the nib, producing a slightly gritty, papery character in the finished bar.

Defines

Cacao nibsNibs are simply what is left after winnowing removes the shell — the raw material of every chocolate there is.
Cocoa shellThe other half of the winnowing output, long treated as waste and increasingly brewed as an infusion.

Flavour developed here

WoodyThis stage is where the note is created, amplified or destroyed. Cedar, oak and dry timber. At low levels a characteristic; at higher levels it usually means shell left in the nib.

Commonly confused with

CrackingDescribed as one step and performed as two. Cracking sizes the fragments; winnowing separates them by airflow, and it can only work on what cracking gave it.

Covered in

Winnowing explainedThe stage record itself.
Bean-to-bar equipmentThe stage that is tedious to improvise and possible to.

Health topics covering this

Chocolate and horsesWinnowing is where the husk is separated, and the volume of husk it produces is why the material ends up in feed and horticulture at all.

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)