Cinnamon
Species

A number of species are often sold as cinnamon:

Cassia induces a strong, spicy flavour and is often used in baking, especially associated with cinnamon rolls, as it handles baking conditions well. Among cassia, Chinese cinnamon is generally medium to light reddish-brown in colour, hard and woody in texture, and thicker (2–3 mm (0.079–0.118 in) thick), as all of the layers of bark are used. Ceylon cinnamon, using only the thin inner bark, has a lighter brown colour and a finer, less dense, and more crumbly texture. It is subtle and more aromatic in flavour than cassia and it loses much of its flavour during cooking.

The barks of the species are easily distinguished when whole, both in macroscopic and microscopic characteristics. Ceylon cinnamon sticks (quills) have many thin layers and can easily be made into powder using a coffee or spice grinder, whereas cassia sticks are much harder. Indonesian cinnamon is often sold in neat quills made up of one thick layer, capable of damaging a spice or coffee grinder. Saigon cinnamon (C. loureiroi) and Chinese cinnamon (C. cassia) are always sold as broken pieces of thick bark, as the bark is not supple enough to be rolled into quills.

The powdered bark is harder to distinguish, but if it is treated with tincture of iodine (a test for starch), little effect is visible with pure Ceylon cinnamon; however, when Chinese cinnamon is present, a deep-blue tint is produced.
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