Saffron

Saffron is the female part of a flower. Each purple Crocus sativus bloom contains one pistil that splits into three bright red stigmas; those three threads, separated from everything else and dried, are the spice. Petals, yellow stamens and the white style are not saffron and are worth nothing.

The plant cannot reproduce on its own. Crocus sativus is a sterile triploid that sets no viable seed, so it has been propagated for thousands of years only by dividing its corms: every saffron plant on earth is a clone passed from field to field.

Italy has three protected designations: Zafferano dell'Aquila DOP on the Navelli plateau in Abruzzo, at 700 metres between the Gran Sasso and the Sirente; Zafferano di Sardegna DOP from San Gavino Monreale, Turri and Villanovafranca in the Marmilla; and Zafferano di San Gimignano DOP in Tuscany, documented in city records since 1228. All three allow whole threads only and forbid powder outright.

Quality is measurable. ISO 3632 grades saffron into categories I, II and III using three lab readings: crocin for colouring strength, picrocrocin for bitterness, safranal for aroma. Category I starts at 190 colouring power; Italian DOP saffron routinely tests above 200 and often above 240, which means you need less of it per dish.

Globally Italy is a rounding error: a few hundred kilos a year against a world crop of two to three hundred tonnes, roughly 90% of it Iranian.

Hay, honey and something faintly metallic and iodine-like, with a bitter edge underneath and a floral sweetness on top. It is not a warm spice, since there is nothing of cinnamon or clove about it, and it is not simply a colouring. Real saffron smells of a barn in summer and tastes slightly medicinal on its own.

Infused into rice, milk or broth it turns the dish orange-gold and leaves a long, faintly bitter finish that keeps butter and cheese from tasting flat. Used with a heavy hand it stops being aromatic and starts tasting like cough medicine, which is why the dose matters as much as the quality. Abruzzese saffron dried over embers carries a light toasted note that oven-dried Sardinian saffron does not have.

Never sprinkle saffron dry onto a finished dish. Its colour and aroma compounds are water-soluble and need time in a warm liquid to come out of the threads.

Either grind the threads in a mortar with a pinch of coarse salt or sugar as an abrasive and dissolve the powder in two tablespoons of warm stock, water, milk or white wine; or better, steep the whole threads in a little warm, never boiling, liquid for twenty minutes, or overnight in the fridge. Use the liquid and the threads together.

Dose 0.1 to 0.15 grams for four people, about fifty stigmas. Doubling it does not double the perfume; it makes the dish bitter and medicinal.

Add it late: in risotto during the last two or three minutes or straight into the final beating-in of butter and Parmigiano; in soup, off the heat; in bread, into the liquid of the dough. Long boiling destroys safranal, the aromatic fraction. Fat and alcohol extract it as well as water, so a milk infusion for a custard works too.

Classic uses: risotto alla milanese; Sardinian malloreddus, fregola and ricotta pardulas; fish soups; mussels and prawns.

Saffron keeps by being kept away from light, heat, air and damp. The right container is small, airtight and opaque, a tin or amber glass rather than a clear jar on an open rack, stored in a cool dark cupboard. Light breaks down the crocin that carries the colour, and warmth drives off the volatile safranal that carries the aroma, which is why a jar by the hob fades far faster than the same jar in a drawer. The fridge is not the answer either, since every opening deposits condensation on the threads.

Whole threads hold on to their strength far longer than ground saffron, which loses its aroma within months. Producers date the jar by harvest year, and the change afterwards is gradual rather than sudden: over two or three years the red dulls towards brown, the perfume flattens, and threads that have taken up moisture stop snapping and turn limp. Keep it away from strongly scented spices, because it picks up their aroma. The harvest year and the producer are the reference.

Buy threads, never powder, because powder is where substitution happens. Each thread is a single stigma: trumpet shaped, flared and slightly ragged at one end, tapering at the other, and deep red along its whole length. Italian DOP saffron from L'Aquila, San Gimignano and Sardinia is sold with the pale style removed, so you should see very little yellow. Dry threads are brittle and snap when pressed. The smell is hay and honey with a metallic edge. Dropped into cold water, real saffron gives up its colour slowly over ten to twenty minutes while the thread itself stays red.

What is sold in its place abroad: safflower, often labelled Mexican saffron, which is flat orange-yellow petals with almost no smell; turmeric; marigold; and dyed corn silk. All of them bleed colour into water instantly and go pale. Price is the clearest signal of all. Real saffron retails around 10 to 30 euro per gram, so jars are sold in tenths of a gram, and a full gram for a few euro is not saffron. DOP jars carry a consortium seal and a harvest year.

In the US, buy from spice specialists who publish origin and harvest year rather than from supermarket jars (Rumi Spice, Burlap and Barrel and Kalustyan's all do) and from Italian importers such as Eataly and Gustiamo, who carry Abruzzese and Sardinian DOP saffron in sealed vials. In the UK, Steenbergs, Sous Chef, Persepolis in Peckham and Italian delicatessens are the reliable route.

Buy whole threads in glass or tin, never loose in a market bag, and check four things on the label: the exact DOP name, ISO 3632 category I, harvest year and net weight in grams. A 0.5 g vial is the sensible first purchase.

Expect roughly 15 to 40 euros per gram for Italian DOP, about 450 to 1,200 dollars an ounce, or 13 to 35 pounds per gram. Good Iranian threads cost a quarter of that, and anything sold as Italian below 10 euros a gram is not Italian. Do the cold-water test at home: real saffron blooms slowly into clear gold and the threads stay red.

Navelli and Civitaretenga, in the province of L'Aquila, at the very end of October and the first days of November. That is the harvest week, and several farms on the plateau let visitors join the evening stripping of the flowers: an hour of it explains the price better than any label. Local restaurants put saffron in everything, ice cream included.

San Gavino Monreale in Sardinia, where the saffron festival runs between November and December and the fields start at the edge of town. Turri and Villanovafranca nearby sell direct from the growers, and trattorie across the Marmilla use it in malloreddus and ricotta pardulas as an everyday ingredient.

San Gimignano in Tuscany, where a handful of farms still grow it among the vineyards. And Milan, for the dish that made it famous: the old trattorie still finish risotto alla milanese to order, and one spoonful separates real threads from a supermarket sachet.