1,8-Cineole
Also written cineole, eucalyptol, 1,8 cineole, eucalyptol (1,8-cineole)
Quick answer
The eucalyptus-and-camphor note found in ten spices here — the compound that makes cardamom cooling, rosemary medicinal, and bay leaf recognisable in a stock you cannot see it in.
What it does
Cineole smells sharply of eucalyptus and camphor and produces a genuine cooling sensation in the mouth and nose, distinct from its smell — a trigeminal effect of the same general kind as menthol’s, though weaker. It is the compound that gives cardamom its cool lift, rosemary and sage their medicinal edge, and bay its clean penetrating quality. In excess it is the reason rosemary and sage taste soapy or like furniture polish when overdone: the threshold between aromatic and medicinal is narrow, and it is crossed by quantity rather than by technique.
How it behaves when cooked
Four properties of the molecule, and what they mean at the stove.
- Volatility
- high
- Fat solubility
- high
- Water solubility
- low
- Heat stability
- moderate
Cineole is volatile but noticeably more persistent than limonene, and that difference in staying power explains a great deal of how these spices are used. In a long braise or stock the lighter, fresher aromatics of bay and rosemary disappear within the first half hour and the cineole remains, which is why a bay leaf is worth adding to a four-hour stock and a basil leaf is not, and why long-cooked rosemary tastes flatter and more medicinal than rosemary added at the end. In cardamom, where the cineole sits alongside a fruitier fraction, this is the argument for using whole pods and cracking them rather than buying ground: pre-ground cardamom keeps its cooling note and loses its sweetness, which is the wrong half. Cineole is also strongly fat-soluble, so rosemary and bay give far more to an oil, a butter or a fatty braise than to a lean poaching liquid.
Spices that carry it
Recorded on the compound rather than on each spice, so the two cannot disagree.
- Bay leafPrincipal component
- RosemaryPrincipal component
- Round cardamomPrincipal component
Up to about seven-tenths of the seed oil, and the source of round cardamom’s cool, eucalyptus smell.
- Black cardamomMajor component
The main component of the seed oil in an analysis of commercial black cardamom, at about 42 per cent. The smoke compounds of fire-drying sit over it, which is why black cardamom is not a substitute for green.
- Green cardamomMajor component
- GalangalMajor component
Given as the main component of the rhizome oil.
- SageMajor component
- AllspiceContributing component
- Grains of SelimContributing component
- KorarimaContributing component
An Ethiopian relative of cardamom with a smokier, earthier profile in which the cineole is present but not the headline.
- LavenderContributing component
- Mexican oreganoContributing component
- MintContributing component
- TsaokoContributing component
Reads as medicinal here rather than as fresh, because it sits under the smoke acquired in fire-drying rather than over a sweet aromatic fraction.
What cooking and processing were measured to do to it
Findings from studies in which this compound was followed through heat, fat, water, drying or storage. Each belongs to its study and its conditions.
Drying · Depends on conditions α-Terpinyl acetate, 1,8-Cineole, volatile oil
In small cardamom dried at three temperatures in a hot-air dryer, the two compounds that carry the characteristic aroma were α-terpinyl acetate, at 61.65 to 68.19 per cent of the oil, and 1,8-cineole, at 7.23 to 11.76 per cent. The abstract reports that esters and alcohols changed more with drying time than the other classes of compound.
Conditions: in air · Three temperatures in a hot-air convective dryer
What this does not show: Read in the abstract only, and the indexed abstract is truncated: it does not say which temperature gave which composition. The ranges show how far the two constituents moved across the dried samples, nothing more.
Measured on the spice
Drying · Depends on conditions 1,8-Cineole, monoterpene hydrocarbons, (E)-2-unsaturated aldehydes, volatile oil, yield
Fruit of Amomum tsao-ko dried at six temperatures gave the highest yield of essential oil at 55 °C and low yields at 85 and 100 °C. The composition shifted with temperature as well: the highest temperatures gave oil richer in monoterpene hydrocarbons, lower temperatures gave more (E)-2-unsaturated aldehydes, and eucalyptol (1,8-cineole), the main constituent, accumulated most in the fruit dried at 100 °C.
Conditions: in air · 25, 40, 55, 70, 85 and 100 °C
What this does not show: Read in the abstract only, which gives no yields. Laboratory drying at fixed temperatures, not the fire-drying over which much of this fruit is traditionally cured.
Measured on the spice
Drying · Decreases α-Pinene, 1,8-Cineole, bornyl acetate, camphene, volatile oil, drying time
Fresh rosemary held 135 g of volatiles per kilogram, chiefly α-pinene, bornyl acetate, camphene and 1,8-cineole. Convective drying lowered the total to 87.2 g/kg and vacuum-microwave drying to 61.9 g/kg. The combined method, convective pre-drying finished under vacuum-microwave, kept 100 g/kg and took about 30 min, and was rated well by a sensory panel.
Conditions: Convective, vacuum-microwave, and convective pre-drying with a vacuum-microwave finish
What this does not show: Read in the abstract only. The ranking of methods here is the reverse of that found for oregano by the same group, so the result belongs to rosemary and should not be generalised to leafy herbs.
Measured on the spice
Drying · Depends on conditions 1,8-Cineole, (Z)-3-hexenal, 3-(methylthio)propanal, phenylacetaldehyde, dimethyl sulfide, borneol, myrcene
In garden sage whose key odorants had been quantified fresh, drying at 50 °C left all the monoterpenes nearly unchanged. The losses fell on other compounds: very volatile ones such as dimethyl sulfide and 2- and 3-methylbutanal decreased, and 3-(methylthio)propanal, phenylacetaldehyde and the green-smelling (Z)-3-hexenal were lost almost completely. Six commercial dried sages had lower concentrations of the key odorants and of total volatiles than the sage dried in the laboratory.
Conditions: in air · 50 °C
What this does not show: Read in the abstract only. One plant grown in a greenhouse and dried under controlled conditions; the commercial samples differ from it in origin and age as well as in drying.
Measured on the spice
Storage · Retains 1,8-Cineole, borneol, myrcene
Sage leaves dried at 50 °C and then stored for twelve months at room temperature in the dark showed little change in the concentrations of the key odorants that were followed. The authors conclude that the drying, and not the storage, was the more important factor for the changes in sage’s aroma compounds.
Conditions: Room temperature · 12 months · Leaves dried at 50 °C, stored in the dark
What this does not show: Read in the abstract only. Whole leaves from one plant, in the dark; the abstract does not describe the container, and says “selected” key odorants without listing them.
Measured on the spice
Not to be confused with
Compounds a reader is likely to take for this one, and why they differ.
Linalool
Isomers sharing the formula C10H18O, one floral and one eucalyptus-like.
Camphor
They travel together in rosemary, sage and lavender and are jointly responsible for what people call the medicinal quality of those herbs. Camphor is the heavier and more persistent of the two and is what remains when a herb has been cooked too long.
Questions this page answers
- what is 1,8-cineole
- what does 1,8-cineole do
- which spices contain 1,8-cineole
- what is cineole
- what is eucalyptol