Reduce (cooking)
Etymology
From Latin "reducere" (to lead back), from "re-" plus "ducere" (to lead). The culinary sense keeps the old idea of bringing something down: you lead the liquid back to a smaller, richer volume by driving off its water.
verb · /rih-DOOSS/
To simmer a liquid so that water evaporates, concentrating its flavor and thickening its body.
What it names
How a thin, watery liquid becomes an intense, syrupy sauce — flavor made denser by patient boiling.
Example
Let the balsamic reduce by half until it coats the back of a spoon like a glaze.
Related idea
Contrast with emulsion: reducing thickens a sauce by removing water, while emulsifying thickens it by suspending fat — different physics, similar richness.
verb · /rih-DOOSS/
To make or become smaller in size, amount, degree, or importance.
What it names
the everyday act of lessening
Example
The company reduced its workforce by a tenth.
Related idea
The kitchen sense is one special case of this broader meaning. Compare mitigate and marginal.
verb · /rih-DOOSS/
In chemistry, to cause a substance to gain electrons — the opposite of oxidation.
What it names
one half of a redox reaction
Example
Iron ore is reduced to metal in a blast furnace.
Related idea
A counter-intuitive sense: to reduce here is to add, not to shrink. Compare fermentation, another everyday chemical transformation.