Not your grandparent’s cinnamon
The cinnamon we eat in the US today is a cheap substitute of the one that was popular in the US prior to the Vietnam war. From USA Today:
In the 1950s, most of the cinnamon Americans consumed was the Saigon variety from Vietnam. Saigon cinnamon – the peeled and ground inner bark of an evergreen tree native to mainland Southeast Asia – has a rich and slightly spicy flavor thanks to high levels of essential oils and a flavonoid called cinnemaldehyde. When the U.S. government imposed a trade embargo on Vietnam beginning in 1964, Saigon cinnamon became almost impossible to import, and spice sellers were forced to find another way to fill American cupboards.
They chose and Indonesian variety, Korintje, that is more bitter and has less depth. Even though the trade embargo has ended, the store-brand cinnamon we use has not recovered.
Commercially available ground cinnamon – almost always the Indonesian Korintje variety – is often mixed with fillers. Scientists at the Indian Institute of Spices Research used a process called DNA barcoding to test market samples. They found that 70% contained powdered beechnut husk, ground hazelnut or almond shell dust, dyed and aromatized using cinnamaldehyde and marketed as cinnamon.
Found via Hayden Higgins.