Today, Caroline Riden is one of the few people in the UK producing the home-grown plant in bulk. As an autumn crocus, the crop will soon be ready for harvest. Then Ms Riden begins the laborious task of hand-picking the three scarlet stigmas from each mauve flower, drying the small, aromatic strands and preparing them for sale - usually to Fortnum & Mason. It takes hours of work, and the stigmas from 150 flowers, to produce one gram of saffron.
Ms Riden lives in North Wales where she and her husband John also raise a suckler herd of Aberdeen Angus. She began growing saffron 10 years ago with 15 corms bought at a garden centre. She planted them in a pot in the greenhouse and was delighted when they flowered the following October. The dried stigmas produced only enough saffron to flavour a dish of rice, but she had established the principle - growing saffron was possible.
"It need not be difficult," she says. "You begin by preparing the soil in a sunny spot. Dig in manure and, as the crocuses prefer a slightly alkaline soil, add a little lime if necessary. Plant the corms between June and August about 12cm (5in) deep and a similar distance apart."
Ms Riden's original experience proves that the plant will also flower in pots. Flowering itself is triggered by a fall in temperature and usually continues for a month or so, but do not expect too much the first year. As each corm matures it produces baby corms, a process known as "dorting"; after four years the plant should be dug up and the small corms removed and planted separately.
Saffron needs to be gathered daily, preferably in the morning. In a garden situation it is better to nip out the three brilliant red stigmas and leave the crocus flower in situ. When you've collected your stigmas, dry them, avoiding both damp and light.
Ms Riden advises first taking off the white base, or style, but this is a matter of taste - leaving it on produces a different "note" in the flavour. The saffron should be wrapped in absorbent kitchen paper and dried in an airing cupboard for two or three days until brittle. It will last up to five years in an airtight container.
British saffron has a sweetness not found in the imported spice. In the home-grown product, the underlying slightly bitter tang is tempered with a honey scent. This adds a distinctive quality to dishes such as bouillabaisse, paella, saffron cake, saffron bread - even potatoes.
Ms Riden recommends using saffron in the form of saffron milk or saffron water. 20 or so strands are toasted for a few seconds in a saucepan and then a tablespoonful of boiling water is added. Allow to cool and then add this concentrate to 150 ml of water or cold milk. This can be stored in the fridge (strain strands out if left for more than 2 days) and will give a golden hue and a delicious flavour to any dishes which require milk or water - it is especially good in pastry for fruit tarts.
Ms Riden has worked out that a supply of 14g should keep an average family in saffron for a year. For this amount 200 corms are needed but, as they dort fast, a mere 20 corms would be quite enough to start with. Ms Riden's corms are naturalised and thus used to our climate; imported corms do not seem to take so kindly to our cooler summers.
For details of saffron cultivation and order forms for corms send SAE to Caroline Riden, Caer Estyn Farm, Rhyddin Hill, Caergwle, Clwyd LL1 9EF.