The Science of Spice

Spices and their Flavour Compounds 13

Using features shared by compounds, I have organised

spices into 12 flavour groups. Their characteristics are

described in the chart below, and we have translated the

groupings into a Periodic Table of Spices on pp14-15.

Some elements of a spice’s taste are not strictly flavour

compounds because they cannot be sensed by the

nose and so have no aroma or flavour. These substances

(technically termed “tastants”) act directly on the tongue,

and include sugars and tart acids. Many are chemicals

intended to deter predators – but which humans can

enjoy – causing bitterness, numbness, coldness, or, in

the case of pungent compounds, spicy heat.

SULPHUROUS COMPOUNDS

Spices in this group tend to be dominated by oniony

and meaty flavours, with cabbage- and horseradish-

like nuances and a degree of pungency. In high

concentrations, sulphur compounds can smell

offensive and fetid.

PUNGENT COMPOUNDS

These sometimes alarmingly hot spices share

compounds that are not flavours at all, but

chemicals that create an illusion of burning by

hijacking pain nerves that normally send warning

signals to the brain above 42°C (108°F).

UNIQUE COMPOUNDS

Some compounds are unique in the world of

spices or do not fit in other groups. Spices

dominated by such compounds can be earthy,

mellow, penetrating, or herby, and usually

partner with a wide range of other spices.

Flavour groups

COMPOUND EXAMPLES

Isothiocyanate in mustard,

diallyl disulphide in garlic.

IN THE KITCHEN

Dispersing in fats, the meaty

taste of these spices helps to

bring depth of flavour to

vegetable dishes.

COMPOUND EXAMPLES

Capsaicin in chilli, piperine in black pepper.

IN THE KITCHEN

Pungent compounds have

varying strengths and agency,

so combine spices for more

rounded heat. Cook with

fats to fully disperse the heat.

COMPOUND EXAMPLES

Picocrocin and safranal in saffron,

tumerone in turmeric.

IN THE KITCHEN

These spices possess

characteristics usually not

found elsewhere and will

bring unique aromas to a dish.

SWEET-SOUR ACIDS

The fruit-based spices in this flavour group

are dominated by sourness from acids, and are

typically accompanied by the sweetness from

plant sugars. Sometimes acids have an aroma,

which can be like cheese or sweat.

FRUITY ALDEHYDES

Aldehyde compounds are found in abundance in

fruiting plants and are more subtle on the palate

than other flavour compound groups. Spices in this

group carry a distinct fruity, malty, or fresh green

flavour, sometimes with fatty or sweaty nuances.

TOASTY PYRAZINES

These spices have been toasted as part of their

processing or gain most of their flavour from

being fried or toasted. Spices in this group carry

nutty, roasted, caramel-like flavours, sometimes

with smoky, meaty, fresh-bread-like nuances.

COMPOUND EXAMPLES

Hexanoic and pentanoic acids in carob,

citric acid in amchoor.

IN THE KITCHEN

Water-soluble and tolerant of long

cooking. Suited to dishes containing

sugar, which amplifies fruitiness

and blunts strong sourness.

COMPOUND EXAMPLES

Nonanal in sumac, hexanal in barberry.

IN THE KITCHEN

Partly water-soluble, but disperse

best in oil and alcohol. Aromas do

not survive high heats or long

cooking times. Cook briefly or

use raw to savour their subtleties.

COMPOUND EXAMPLES

Each spice develops a unique combination

of dozens of pyrazines.

IN THE KITCHEN

Create pyrazines by dry-toasting

spices over 130°C (266°F). Flavours

spread best in oil and enhance

savoury dishes, in particular.

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