Making and keeping your own spice blends

A whole spice is a container. The aromatic compounds that carry flavour sit inside a seed coat, a bark, a pod or a dried fruit wall, and that structure is what keeps them there. Grinding destroys it and exposes the entire interior surface to air at once.

The practical consequence is a difference of years against months. Whole cumin, coriander, caraway and black pepper commonly hold up for two years or more; ground, most are noticeably diminished within six to twelve months and ground cardamom within three. The spread is large enough that a cheap whole spice ground fresh reliably beats an expensive pre-ground one that has been open a year.

This is why making your own blends is worth the effort in a way most kitchen projects are not. You are not chasing a better recipe — commercial blends are often perfectly well formulated — you are moving the grinding from the factory to the week you use it.

There are honest exceptions. Turmeric and dried chilli are hard to grind domestically. Cinnamon and cassia bark defeat most home grinders. And some spices belong in a blend whole: panch phoron is five whole seeds by definition, and grinding it makes something else entirely.

Toast each spice separately. This is the step most often skipped and the one that most affects the result: seeds of different sizes and oil contents reach the right point at very different times, so a pan of mixed spices always contains something scorched and something raw. Small seeds like ajwain and celery seed take seconds; coriander and cumin take a minute or two; dense items like cassia bark barely toast at all.

Toast dry, over a moderate heat, moving the pan constantly, and stop when the aroma changes rather than when the colour does. Burnt spice is acrid and there is no recovering it.

Cool completely before grinding. Warm spices sweat inside a grinder and the powder cakes.

Grind together once cool, and sieve if the blend wants an even texture. Some components never fully break down — fenugreek is notoriously hard, and dried chilli skin tends to flake rather than powder.

Add the ground components last. If a blend contains something already ground, such as turmeric, stir it in after rather than putting it through the grinder, where it adds nothing and costs aroma.

A mortar and pestle is the traditional answer and remains the best one for small quantities and for anything fibrous or oily. It handles galangal, long pepper and lemongrass that would damage an electric grinder, and it lets you stop at coarse when coarse is wanted — dukkah and za'atar both depend on a texture a blade grinder would destroy.

Failing that, several ordinary things work. A rolling pin over spices in a folded tea towel or a sealed bag gives a coarse crush that suits juniper, coriander and peppercorns. The flat of a heavy knife pressed down and rocked will crack cardamom pods, juniper berries and garlic. A sturdy mug or the base of a heavy pan against a chopping board does the same job more crudely.

A microplane or fine grater handles hard dense items — nutmeg above all, and long pepper, which is too dense for a mill.

What does not work well is a food processor for small quantities: the blades pass over the spices rather than through them and you end up with a mixture of dust and whole seeds. A dedicated blade grinder, or an old coffee grinder kept for spices, is inexpensive and is the single most useful piece of equipment for anyone making blends regularly.

One caution about shared equipment. Spices leave their aroma in a grinder, and coffee ground after cumin tastes of cumin. Grinding a little rice or stale bread cleans a blade grinder reasonably well, and keeping separate ones is better.

Airtight, opaque, cool and dry, and away from the hob. The most convenient place in a kitchen is directly above the cooker, and it is the worst: heat, light and steam are precisely what degrade aromatics, and a jar kept there will fade in a fraction of the time.

Glass or metal rather than plastic, which absorbs aroma and gives it back to whatever goes in next.

Label with the date you mixed it, not the date you bought the components. A blend is as old as its grinding, and the printed date on a jar of shop-bought powder describes an unopened package rather than what is in front of you.

Make small quantities. A month or two of a blend you use often is the right scale; a large jar of something you use twice a year is a way of storing disappointment. This is the single most common mistake with home blending, and it is the opposite of the instinct that made you start.

Some blends do not keep at all in the ordinary sense. Dukkah contains crushed nuts and toasted sesame and goes rancid rather than stale, which is a matter of weeks rather than months — treat it as a perishable nut product and keep it cold. Anything containing salt draws moisture and cakes; anything containing dried garlic or onion does the same, faster.

The useful principle is that storage conditions matter more than arrangement. A beautiful rack in direct sunlight is worse than a shoebox in a cupboard, and a tiered shelf above the cooker is worse than either.

Beyond that, arrange for what you actually do. Alphabetical works if you own many and cook across cuisines; grouping by cuisine works better if you cook the same handful of dishes, because you reach for the same five or six jars together. Separating whole from ground is worth doing whatever else you choose, since they have such different lifespans that mixing them makes it hard to keep track.

Decant into uniform jars if you like, and label them with contents and date. The date is the part that does the work.

Keep the collection small enough to turn over. A cupboard of thirty jars used twice a year is thirty stale jars, and the fix is buying less rather than storing better.

Most traditional blends have no fixed formula, and SpiceHQ records variants rather than recipes for exactly that reason. Garam masala differs by household; ras el hanout differs by merchant; berbere differs by family. There is no authentic version to reproduce, which is liberating once you stop looking for one.

A workable approach is to start from a recorded variant, mix a small batch, cook with it, and adjust once. Note what you changed. Two or three iterations gets most people to a blend they prefer to anything they can buy.

A few structural rules hold across most blends. Cloves, black cardamom and asafoetida dominate quickly and should be scaled up cautiously or not at all when you multiply a batch. Salt-containing blends need their salt tracked separately from the dish. And anything with a large chilli fraction needs the specific chilli identified, because heat varies several-fold between varieties and a blend rescaled with a hotter one is not stronger but inedible.

Panch phoron is the exception that proves the point: five seeds in equal parts, everywhere, with nothing to adjust.