SAFFRON OIL Crocus sativus L. ,crocus cartwrightianus
Kesar , Zaffran 
Very intensively fragrant (reminiscent to iodoform, but much more pleasant), slightly bitter in taste. By soaking saffron in warm water, one gets a bright yellow-orange solution.
Minimum saffron colour grading standards (ISO 3632) |
|
|---|---|
| ISO Grade (category) |
Crocin-specific absorbance (Aλ) score (at λ=440 nm) |
| I | > 190 |
| II | 150–190 |
| III | 110–150 |
| IV | 80–110 |
The saffron crocus thrives in climates similar to that of the Mediterranean maquis or the North American chaparral, where hot, dry summer breezes blow across arid and semi-arid lands. Nevertheless, the plant can tolerate cold winters, surviving frosts as cold as −10°C and short periods of snow cover. However, if not grown in wet environments like Kashmir (where rainfall averages 1000–1500 mm annually), irrigation is needed—this is true in the saffron-growing regions of Greece (500 mm of rainfall annually) and Spain (400 mm). Rainfall timing is also key: generous spring rains followed by relatively dry summers are optimal. In addition, rainfall occurring 
immediately prior to flowering also boosts saffron yields; nevertheless, rainy or cold weather occurring during flowering promotes disease, thereby reducing yields. Persistently damp and hot conditions also harm yields, as do the digging actions of rabbits, rats, and birds. Parasites such as nematodes, leaf rusts, and corm rot also pose significant threats.
Saffron plants grow best in strong and direct sunlight, and fare poorly in shady conditions. Thus, planting is best done in fields that slope towards the sunlight (i.e. south-sloping in the Northern Hemisphere), maximizing the crocuses' sun exposure. In the Northern Hemisphere, planting is mostly done in June, with corms planted some 7–15 cm deep. Planting depth and corm spacing—along with climate—are both critical factors impacting plant yields. Thus, mother corms planted more deeply yield higher-quality saffron, although they produce fewer flower buds and daughter corms. With such knowledge, Italian growers have found that planting corms 15 cm deep and in rows spaced 2–3 cm apart optimizes threads yields, whereas planting depths of 8–10 cm optimizes flower and corm production. Meanwhile, Greek, Moroccan, and Spanish growers have devised different depths and spacings to suit their own climates.
Saffron crocuses grow best in friable, loose, low-density, well-watered, and well-drained clay-calcareous soils with high organic content. Raised beds are traditionally used to promote good 
drainage. Historically, soil organic content was boosted via application of some 20–30 tonnes of manure per hectare. Afterwards—and with no further manure application—corms were planted.[13] After a period of dormancy through the summer, the corms send up their narrow leaves and begin to bud in early autumn. Only in mid-autumn do the plants begin to flower. Harvesting of flowers is by necessity a speedy affair: after their flowering at dawn, flowers quickly wilt as the day passes.[14] Furthermore, saffron crocuses bloom within a narrow window spanning one or two weeks.[15] Approximately 150 flowers yield 1 g of dry saffron threads; to produce 12 g of dried saffron (72 g freshly harvested), 1 kg of flowers are needed. On average, one freshly picked flower yields 0.03 g of fresh saffron, or 0.007 g of dried saffron
