Blooming spices

What the heat and the fat do

Most of the aroma in a spice sits in volatile compounds that are fat-soluble and locked inside the cell structure of the seed or bark. At room temperature very little escapes.

Heat drives them out and, crucially, fat dissolves them and carries them through the dish. A spice stirred into a watery sauce releases some of its flavour; the same spice fried in oil for thirty seconds first releases far more, and it is distributed evenly rather than sitting in pockets.

Heat also creates new compounds. Toasted cumin does not taste like a more intense version of raw cumin — it tastes different, nuttier and rounder, because the heat has changed it.

Blooming in fat

The Indian technique is called a tadka or chaunk and the same principle works everywhere.

1. Have everything ready before you start. This happens in seconds and there is no time to fetch anything.
2. Heat oil or ghee in a small pan over a medium heat until it shimmers.
3. Add whole spices first — mustard seed, cumin, fennel, coriander, dried chilli, curry leaves, cinnamon, cardamom.
4. Wait for the cue: mustard seeds pop and jump, cumin sizzles and darkens slightly, curry leaves crackle. Ten to thirty seconds.
5. Add ground spices last and only for a few seconds. Ground spices burn almost instantly — turmeric and chilli powder are the fastest.
6. Then add the aromatics or tip the whole thing over the finished dish.
7. If anything goes dark brown or smells acrid, throw it away and start again. Burnt spice cannot be diluted out.

Whole against ground, and dry against fat

Whole spices in fat

Ten to thirty seconds. The most forgiving and the most flavourful.

Ground spices in fat

A few seconds only, and off the heat if in doubt. They burn very fast.

Dry-toasting whole spices

In a dry pan until fragrant, then ground. Best for a spice mix that will be stored.

Turmeric and chilli powder

The quickest to burn. Add them last or off the heat.

Ginger and garlic

Not spices in this sense — they contain water and go in after the spices, not with them.

Order

Slowest first. Hard seeds, then softer ones, then leaves, then ground spices.

Where it belongs

• The start of a curry, where the spices go into the oil before the onions.
• A tadka poured over a finished dish — dal, yoghurt, a vegetable side — at the last moment, which is a separate and equally important use.
• Toasting cumin, coriander or fennel before grinding for a spice mix.
• Chilli oil, where the oil temperature decides whether the chilli blooms or scorches.
• Mexican cooking, where dried chillies are toasted before soaking.
• A pilaf or biryani, where whole spices go into the fat before the rice.
• Not into a cold dressing, where a bloomed spice oil added afterwards works far better than raw powder.

Common questions