Cinnamon

Cassia is in the Chinese record from the beginning. The Shennong Bencao Jing, compiled around 200 CE, carries two cassias in its upper class, 牡桂 and 菌桂, and later writers spent centuries arguing about which tree each name meant. What survived the argument is the distinction the tradition still makes, and it is the one thing worth carrying away from this page: the bark and the twig of the same tree are two different items with two different jobs.

肉桂 ròuguì is the thick inner bark of a mature trunk. It is hot, it is sweet under the heat, and Chinese medicine reads it as warming slowly and deeply, at the Kidney end of the body — the low back, the knees, the cold that sits under everything. 桂枝 guìzhī is the young twig, thin and far milder, and the tradition reads it as moving outward toward the surface and the limbs. A Chinese herbal shop keeps them in separate drawers at very different prices. A Western supermarket sells the bark, in quills, and calls it cinnamon.

The twig is the more famous of the two, because Zhang Zhongjing built the opening formula of the Shanghan Lun on it. That book was written around 200 CE after an epidemic killed most of his clan, and of its 398 clauses the twelfth gives 桂枝汤 guìzhī tāng, Cinnamon Twig Decoction, made of five things a kitchen already has. What is striking about the clause is not the formula but the instruction underneath it, which is a cook’s instruction rather than a physician’s.

Li Shizhen filed the tree among the fragrant woods when he printed the Bencao Gangmu in 1596 — 1,892 entries gathered over twenty-seven years — and set the bark and the twig out as separate entries so that no later reader could go on taking them for one thing. He is emphatic that thickness and oiliness are what mark good bark, and that a quill which has lost its smell has lost the point of itself.

One botanical note, because it decides what you buy. Chinese medicine has always meant cassia, Cinnamomum cassia, the hard dark quill that snaps. Ceylon cinnamon, Cinnamomum verum, is a softer, paler, many-layered bark from a different species, and it is not the item in any Chinese text on this page. The difference matters twice: once for what the tradition is describing, and once for the caution at the foot of this page.

In a Chinese kitchen cassia bark is a braising spice, not a drink. It goes into the pot whole, at the start, with ginger and spring onion, and it is lifted back out before the dish reaches the table. Winter food, and Sunday food: the pot that goes on at two and is eaten at six. The classic partner is beef and daikon, which is a cold-weather dish across most of northern China.

The domestic shortcut is smaller still: a sliver of bark dropped into a pot of dates and ginger on a cold morning, or a pinch of ground cassia stirred through millet porridge. That is the whole of it. This is not an entry that turns into a daily drink, and the tradition has never used it that way.

Cassia bark is the hottest item on this list, and heat is a direction rather than a virtue. It suits a person who is cold underneath and does not suit a person who is already running hot — and unlike ginger, which warms briefly and near the surface, this one warms slowly and stays.