Does Real Cinnamon Float? The Science of the Water Test

January 6, 2026 •

4 min read

The hydrophobic properties of ground cinnamon mean it naturally repels water, causing it to float, a principle often demonstrated in fun science experiments. This fundamental scientific characteristic is the basis for a popular at-home water test used to differentiate cinnamon types and spot adulteration.

Quick Summary

This article explores the popular cinnamon water test to distinguish varieties. Due to its hydrophobic nature, real Ceylon cinnamon tends to float longer, while cheaper Cassia may sink more quickly or clump, revealing key differences between them.

Key Points

Floating Test Isn't Definitive: While real Ceylon cinnamon tends to float longer due to its hydrophobic properties, the test is not foolproof and other factors like age and fineness of grind can influence results.
Hydrophobic Nature: Cinnamon powder naturally repels water because it is tree bark containing water-insoluble essential oils like cinnamaldehyde.
Ceylon vs. Cassia: The two main types of cinnamon behave differently in water; true Ceylon floats and mixes slowly, while Cassia can sink quicker, especially if adulterated.
Look Beyond the Water Test: The most reliable identification methods include inspecting the stick's structure (multi-layered Ceylon vs. single-layer Cassia), checking the label, and comparing aroma and taste.
Health and Coumarin Content: Ceylon cinnamon has very low levels of coumarin, making it the safer choice for frequent or high-volume consumption, while Cassia contains high levels that can be harmful.
Visual Confirmation: Authentic Ceylon cinnamon sticks are delicate and easy to break, while Cassia sticks are thick and hard.
Price Matters: If the price seems too low for 'real cinnamon', it is likely the cheaper, common Cassia variety.

The Science Behind Floating Spices

To understand why a spice like cinnamon behaves the way it does in water, you must first grasp the concept of hydrophobia. The term 'hydrophobic' literally means 'water-fearing.' It describes substances that do not mix with, or are repelled by, water. Cinnamon's flavor is derived from its essential oils, most notably cinnamaldehyde, which are not water-soluble. As a natural product made from the inner bark of a tree, cinnamon's fibrous material is designed to shed water, not absorb it. When powdered, these microscopic, oil-coated bark particles create a barrier that prevents the spice from becoming easily saturated, allowing it to rest on the surface tension of the water.

The Cinnamon Water Test Explained

This simple test can help you get a better idea of what's in your spice jar, though it is not a definitive proof of authenticity on its own. Here's how to conduct the experiment:

Fill a clear glass with room-temperature water.
Take a small, level pinch of your cinnamon powder.
Gently sprinkle the powder onto the surface of the water.

What to look for:

Ceylon Cinnamon (True Cinnamon): Because of its finer, more delicate composition and higher oil content, true Ceylon cinnamon will typically float on the surface for a sustained period. It may slowly begin to mix or sink, but it will not dissolve.
Cassia Cinnamon (Common Cinnamon): The bark of Cassia is thicker and tougher, and its coumarin-rich essential oils are often not as readily dispersed. When placed in water, Cassia may absorb water more quickly and often begins to sink faster than Ceylon. If it is adulterated with cheaper fillers like starch or flour, it may sink very rapidly or form a sticky paste at the bottom of the glass.

Ceylon vs. Cassia: Beyond the Water Test

While the floating test provides a useful clue, relying on it exclusively is not recommended. The results can vary depending on the powder's age, grind fineness, and how it was dried. A more holistic approach involves comparing Ceylon and Cassia across several key characteristics.

Comparison Table: Ceylon vs. Cassia Cinnamon


Feature	Ceylon Cinnamon (True)	Cassia Cinnamon (Common/Fake)
Origin	Sri Lanka, Southern India	China, Indonesia, Vietnam
Appearance	Light tan-brown, many soft, fragile layers	Dark reddish-brown, single, hard layer
Aroma	Mild, sweet, and subtle, often with floral or citrus notes	Strong, pungent, and spicy
Taste	Delicate and slightly sweet	Intense, often slightly bitter or astringent
Coumarin Content	Very low, considered safe for regular consumption	High, potentially harmful in large quantities
Water Test	Tends to float and mix slowly	Tends to sink quicker, may form a paste

Other Reliable Methods to Identify Real Cinnamon

For accurate identification, combine the water test with these other observations:

Visual Inspection (Sticks): Observe the stick's structure. True Ceylon cinnamon sticks are composed of multiple thin, paper-like layers rolled together, resembling a delicate cigar. Cassia sticks are made from a single, thicker, and much harder layer of bark rolled into a hollow scroll.
The Break Test: Try to snap a cinnamon stick. Ceylon cinnamon is brittle and breaks easily with your fingers, while Cassia is tough and woody and requires significant force to break.
Label Reading: The most reliable method is to read the packaging. Look for 'Ceylon cinnamon' or the scientific name Cinnamomum verum. If the label simply says 'cinnamon' or lists the origin as China or Indonesia, it's almost certainly Cassia.
Price: Ceylon cinnamon is more expensive due to its delicate nature and intensive harvesting process. A suspiciously low price is a major red flag that you are buying Cassia.

Conclusion: So, Does Real Cinnamon Float?

The short answer is yes, real Ceylon cinnamon does tend to float, primarily due to its natural water-repelling essential oils and fine, porous structure. However, it is a nuance-filled test and should not be your only method of authentication. The floating test, when used in conjunction with visual inspection, aroma checks, and mindful label reading, is a great tool for the informed consumer. Understanding the distinct differences between delicate Ceylon and robust Cassia ensures you select the right spice for your culinary needs and health concerns. The higher concentration of coumarin in Cassia, which can be toxic to the liver in large doses, makes Ceylon the safer choice for frequent consumption. For more details on the health benefits of true cinnamon, review information from reliable sources like the National Institutes of Health Medicinal properties of 'true' cinnamon (Cinnamomum zeylanicum).

Note: While cinnamon may float initially, it is not a substance that dissolves. Any clumping or eventual sinking is a function of the powder becoming saturated or the essential oils dispersing, not it dissolving like sugar.

Frequently Asked Questions

Cinnamon floats on water because its particles are hydrophobic, meaning they repel water. The spice is tree bark containing natural essential oils, and these oils and the fibrous structure prevent the powder from absorbing water and breaking the water's surface tension, causing it to float.

The water test suggests that finer, lighter Ceylon cinnamon tends to float longer, while the denser, thicker-barked Cassia cinnamon may sink more quickly. If adulterated with fillers like starch, Cassia powder might even form a sticky paste or sink rapidly.

No, the water test is a useful but not entirely reliable indicator of cinnamon authenticity. Factors like the age and fineness of the grind can affect the result. For accurate identification, the test should be combined with other methods such as visual inspection of the sticks, smell, and taste.

Ceylon cinnamon sticks are composed of multiple thin, fragile, paper-like layers rolled into a cigar-like shape. Cassia sticks, in contrast, are a single, thick, hard layer of bark that forms a hollow, scrolled tube.

The main reason is health. Cassia cinnamon contains high levels of a compound called coumarin, which can be toxic to the liver if consumed in large quantities over time. Ceylon cinnamon has negligible coumarin, making it the safer option for frequent or daily use.

Real Ceylon cinnamon has a mild, sweet, and complex aroma with notes of citrus. Its flavor is delicate and subtly sweet. Cassia cinnamon has a much stronger, more pungent, and spicy scent and an intense, often bitter or astringent taste.

To ensure you are buying real Ceylon cinnamon, look for 'Ceylon cinnamon' or the scientific name Cinnamomum verum explicitly mentioned on the packaging. If the label only says 'cinnamon' or lists a country of origin like Indonesia or China, it is most likely Cassia.