There are two main varieties of cinnamon, Ceylon and Cassia. Cassia can also be further broken down into Korintje, Vietnamese and Chinese Cassia.
Also known as 'true cinnamon,' Mexican cinnamon, or canella, ceylon is not readily available in American grocery stores. It is lighter in color and in flavor. Ceylon is considered a finer quality spice and its price reflects that. Unlike cassia, the sticks are very delicate and can be easily broken. If possible, buy only sticks and grind yourself as needed to protect the delicate oils. Ceylon is recognized to have a note of citrus and is best used in lightly flavored dishes where the nuanced flavors can stand out.
This is the cinnamon that is most available in American grocery stores. However, not all Korintje cinnamon is created equal. As with all spices, we recommend you visit a specialty spice shop for the highest quality. In comparison to other varieties, Korintje is considered a bit sharper and more bitter. If you are looking for cinnamon sticks to use in potpourri or as stir-sticks for apple cider, Korintje is a good choice.
Vietnamese cassia is the most pungent spicy cinnamon. It has a cinnamon flavor that is more reminiscent of cinnamon candy.
Chinese cassia has a sweet flavor that blends nicely and thus is great for baking.
Note: Cassia is reported to contain high levels of a toxin called coumarin. Coumarin could cause liver damage. If you have liver issues, or plan to eat large quantities of cinnamon, stick to Ceylon.