The quills, which may be incompletely dried, may be recleaned, washed in fresh water, thoroughly dried and packed. Good Chinese cassia bark is sweet and aromatic, resembling Ceylon cinnamon in flavour, but is rather less delicate and sometimes slightly astringent; it is less uniformly thin and darker in colour; the outer bark is often less carefully removed, leaving patches of rough, greyish bark.

The bark is removed from the standing tree at the time when it lifts easily, starting with the main branches and working down the trunk. A bambdo scaffolding may be erected for the purpose. Horizontal cuts are made about 40 cm apart and vertical cuts some 25-35 cm apart. The rectangles of bark are then removed with the aid of a horn or bamboo spatula. Finally, the tree is felled and the inferior bark removed from the smaller branches. A stump may he left to encourage coppicing.

In comparison to cinnamon bark oil, the production of cassia bark oils is on a relatively small scale with distillation being undertaken in the importing countries. These oils find a limited use in soaps, perfumes, some spice essences and beverages.

The tree grows on a variety of soils, the best areas being well-drained sides of valleys, where lateritic soils of old volcanic origin run down to alluvial soils in the valley bottoms. The rainfall of these areas is high, reaching 2 500-3000 mm per annum, and this is said to be essential for the production of good-quality bark. Saigon cassia is also grown in the plains, both in plantations and in gardens mixed with other crops, such as bananas, areca nuts and jack-fruit.

Cassia oil of commerce is produced in China. It contains cinnamaldehyde as its major constituent and is used for similar purposes to cinnamon bark oil in perfumery and flavouring (after rectification) but its applications are rather more limited.

The major use of cinnamon and cassia barks, both in whole and ground forms, on a world-wide basis is for domestic culinary purposes, which in the industrialized Western countries the major outlet is in the flavouring of processed foods. The spices are traded internationally in the whole form and grinding is carried out in the consuming centres. The ground spices find application in the flavouring of bakery products, sauces and pickles, puddings, curry powder, some beverages and confectionery. The preference for cinnamon or one of the three types of cassia in particular applications varies from country to country. The four species are often blended during grinding to prepare a mixed cinnamon/cassia ground spice.