According the Austrian Food Law, the term
spice refers to plants or parts
of plants (possibly dried) that are used to enhance the flavour or taste of
human food. Apart from the measures necessary for conservation, spices must not
be technically modified or mixed with any other components (the law applies
special names to such mixtures).
It will be seen that this definition is rather narrow: Many ingredients serving exactly the same purpose as spices, like beef extract, dried fish, fish sauce, shrimp paste, soybean sauce or fermented wheat, are excluded. This is probably because, with the exception of beef extract, these preparations have no tradition in Central Europe, at least not in our times. Of course, also salt is not considered a spice.
It will also be noted that this definition does not make any distinction
between herbs and spices, as seems to be common in English language.
Thence, the meaning of herb will refer to a subset of the
meaning of spice in all documents on this site, or, put the
other way, the meaning of spice will include tropic plants with
aromatic fruits or barks (traditionally called
spices) and plants of
temperate climate featuring aromatic leaves (traditionally called
herbs). You might call that bad and idiomatically incorrect English,
and you’ll be right with this critique; still, that’s the price native
English speakers have to pay for the advantage of reading the Internet
in their mother tongue (please let me make perfectly clear that this is
no private war against English language, but simply a statement
about the dynamics of living languages).
Although at most forty different spice plants are of global importance (economically and culinarily), many more are used as condiments locally, in the region of their natural occurrence. Some of these are traded in small quantities and used in ethnic restaurants or by emigrants who do not forsake their cooking traditions, other have some use as medicine and are therefore available in western pharmacies. Many spices that have been used extensively in past centuries in Europe have now become obsolete and are now not even known to the Western public – mostly because other spices with similar sensory quality became cheaper and were preferred. It is my interest to gather information about well-known and well-researched spices as well as about those exotes.
At present, I own dried samples of about 117 different spice plants (and of course a lot more that I could not yet identify). This is, however, only a small fraction of the total number of plants used throughout the world: Especially in tropic regions, lots of local plants growing abundantly without cultivation are used for traditional cooking, and these are mostly not even researched, yet traded in significant scale.
About the main constituents in spices, quite a lot should be said, or nothing at all; this is a very large field and easily confused by superficial discussions. Still, I want to explain some of the terms that appear frequently in my spice articles.
The constituents responsible for the spicy properties of plants are always secondary metabolism products; this is, they are not involved in primary metabolism (production of plant tissue and production/use of energy storing molecules); thus, they are not vital for the plant. In some case, it is supposed that the aroma molecules are essentially by-products of metabolism; in most cases, though, they play an important rôle in attracting pollinators or drive away herbivorous animals. It is somehow paradoxical that plants are grown and spread world-wide as food enhancers, although their tasty constituents’ intention is to discourage the consumption of the plant.
Although there is a large number of classes of plant constituents known, most plants contain only few of them. It is frequently observed that botanically related plants contain similar or even the same constituents; this also explains why spices appear clustered in some plant families, while other families do not contain any aromatic plant.
Only a small fraction of the many biochemicals found in plants are relevant for the quality of spiciness; many classes are hardly ever found in spices, as their taste in unpleasant or they are not safe at all. The following classes are most important culinarily:
This is by far the most important class of aroma compounds. Many of them exhibit an aromatic fragrance reminiscent to turpentine (which is a terpene mixture distilled from various fir species).
Terpenes are widely distributed secondary metabolism products, showing low boiling point and, thus, strong aroma. The name terpene properly is reserved for hydrocarbons made up from isoprene units, but is frequently extended to derivatives of these (alcohols, ethers, carboxylic acids, esters …), which should be called terpene derivatives. Furthermore, benzoid dehydration products of terpenes appear in plants, e. g. the phenol thymol, which is responsible for the aroma of thyme and ajwain.
Depending on molecule size, we discriminate between mono-, sesqui-, di- and triterpenes, having 10, 15, 20 and 30 carbon atoms, respectively. Of these groups, monoterpenes are of utmost importance; 90% of all spices owe their fragrance to them. Nearly all monoterpenes are not specific for a species, but occur in many different plants; thus, the characteristic aroma of a spice is caused by a specific mixture of monoterpenes, not by a specific individual compound. Monoterpenes are formed in all plant families, but are most numerous and highly-concentrated in the mint family (Lamiaceae) and the parsley family (Apiaceae), both of which contain a large number of spice plants.
Given their large number, it is amazing that only a few monoterpenes exhibit severe toxicity for humans, although quite many may cause skin irritation. Most of the toxic monoterpenes are actually ketones; examples include umbelliferone (from California Bay leaves), pulegone (from pennyroyal) and a number of furanoid terpene ketones found in perilla, e. g., isoegomaketone.
Thujone (in mugwort, wormwood, sage and many cypress species) is commonly made responsible for the adverse effects of the absinth liquor popular at the begin of the 20.th century (see southernwood). Another example of a toxic monoterpene ketone found in many spice plants is camphor, a pleasantly-scented, but quite dangerous substance. Camphor is found in many spices of the mint family (e. g., rosemary or sage).
organicinsecticide pyrethrum should be mentioned; pyrethrum and its derivatives are monoterpenoids with anomalous structures; they are effective insecticides, but hardly toxic for mammals. A most untypical monoterpene is cantharidine, which is won not from a plant but from a kind of bug called
Spanish fly; it is occasionally abused as an aphrodisiac. Amazingly, cantharidin is extremely toxic for humans, but much less for other mammals.
Higher terpenes are less volatile and, therefore, of less olfactory importance. While sesquiterpenes are moderately common constituents in aroma plants (though in small concentrations), di- and triterpenes are rather exotic and rare in spices. Among the sesquiterpenes some are common to many families, but generally, the higher terpenes tend to be specific to a family, genus or even species. Sesquiterpenes are of some importance for the fragrance of cinnamon, conifers (juniper) and take an important part in the aroma of ginger and other plants of the ginger family (Zingiberaceae), like turmeric and galangale.
Polygodial (tadeonal) is an unusual sesquiterpene derivative; despite being nonvolatile, it has culinary value. Polygodial is a partially unsaturated dialdehyde and has an intensive, biting hot taste; both water pepper and Tasmanian pepper owe their pungency to that compound.
Di- and triterpenes tend to taste strongly bitter; a mixture of phenolic di- and triterpenes is responsible for the slightly bitter taste of several spices of the mint family (Lamiaceae); see also hyssop. Many diterpenes are pharmacodynamically very active, which means that they can be effective medicines or effective poisons, depending on circumstances. For example, the toxicity of the infamous
Pontic honeyfrom the Turkish Black Sea coast is due to traces of diterpenes contained in the nectar of local Rhododendron species.
Triterpene glycosides are known as saponins, and some of them are highly toxic due to their haemolytic power, but due to poor resorption this does usually not apply to oral route. Glycyrrhizin (from licorice) is a rare example of a saponin with pleasant taste.
Of the tetraterpenes, the most important group are carotenoids. This term includes characteristically (yellow to orange) coloured unsaturated tetraterpene hydrocarbons and derivatives of such hydrocarbons; all plants contain carotenoids, and several vegetables and fruits owe their orange colour to them. Usually, they are soluble in fat; thus, small drops of oil will take up the entire colour in soups or sauces spiced with paprika. A rare example of a water-soluble carotenoid is found in saffron.
This class of aroma compounds is rather small and appears most frequently in the magnolia order (Magnoliidae), e. g., cinnamic acid in cinnamon; but phenylpropanoids are by no means restricted to that class. Other representatives include the toxic safrol (also spelt safrole; see sassafras, nutmeg), and eugenol (cloves); yet another related compound is vanillin in vanilla beans. Lastly, coumarin (woodruff, tonka bean) must be mentioned as a wide-spread phenylpropanoid. Similar to terpenes, phenylpropanoids are frequently volatile; essential oils, which are won by distillation, are mostly made up from these two classes of compounds.
This group of non-volatile compounds is only found in the rhizomes (rootstocks) of spices of the ginger family (Zingiberaceae), e.g., zedoary and fingerroot; diarylheptanoids are responsible for the pungent taste of these spices and for the yellow colour of turmeric.
Biochemically, they are related to phenylpropanoids; their basic structure, though substituted and modified in numerous ways, is 1,7-diarylheptan-3-one. Structurally related but simpler 1-aryl-alkanones appear in ginger and grains of paradise.
This important class of biochemicals contains several well-known poisons and medicines (atropine from belladonna, morphine from poppy, cocaine from the South American coca shrub and coniine from hemlock, just to name a few). Because of high toxicity and generally bitter taste, they are rarely found in spices, and then mostly not responsible for the taste (e. g., nigellin in nigella or boldin in boldo leaves). Yet the pungent principles of chiles and black pepper are closely related to alkaloids. Since they are mostly not volatile, alkaloids do not exhibit aroma and do not show up in essential oils.
This is a large and inhomogeneous group of biochemicals. Their common feature is that they consist of two parts: A carbohydrate (sugar), mostly glucose, and another, non sugar-like part, which is generally termed aglycon. According to the chemical identity of the aglycon several types of glycosides are discriminated; it is important to realize that the chemical bond binding the sugar to the aglycon (called glycosidic bond) is weak and easily cleaved, yielding the free aglycon. Glycosides are generally non-volatile and thus lack fragrance, but the aglycon itself may well be volatile and, then, show up in the essential oil.
Some plants store aggressive compounds, which could be harmful for the plant itself, in form of glycosides; the dangerous substance can, if needed, produced readily by enzymatic reaction. A well-known example are cyano-glycosides contained in the seeds of apricots, cherries or bitter almonds; on cleavage of the glycosidic bond, they yield the highly toxic hydrocyanic acid.
A similar example are mustard oil glycosides, which are found in the cabbage family (Brassicaceae): Their aglycon is a pungent and lachrymatory isothiocynate, which is, in its free form, stable for only a few minutes. These glycosides are contained in black and white mustard seeds and in horseradish.
Coumarin (e. g., in woodruff or tonka beans) and vanillin (in vanilla beans) are examples for aroma compounds which are stored as glycosides and are liberated only by drying. To convert the scent-less glycoside to the aroma compound as quantitatively as possible, these two spices need extensive post-processing after plucking.
Members of this inhomogeneous class of biochemicals are found in nearly all plant families; their taste is astringent and rather unpleasant. Thus, they are not valued in spice plants. High tannine content is considered a sign of bad quality (see cassia), but in small amounts, even tannine has some culinary merits (see rosemary, sumac).
- Fruit acids:
This term includes some chemically related di- and tricarboxylic acids, of which citric acid is, before tartric and malic acid, the most important. All these acids feature the same, purely sour taste and lack specific fragrance; the typical aroma by which we distinguish between lemon, orange, pomegranate or mango is solely determined by other, volatile compounds.
- Carbon hydrates:
All green plants are capable of synthesizing sugars (primarily, glucose) from water, air and light; glucose, in turn, acts as a kind of fuel, which can be combusted and thereby yields energy. Other sugar types are produced from glucose. Sweetness of fruits serves to attract animals to spread the seeds; they frequently contain, besides glucose, the chemically related fructose.
Storing large amounts of sugar in a plant cell is not feasible; on the other hand, many plants need to store the energy content of glucose, e. g., over winter, to allow rapid growth in spring. A suitable compound to store glucose is starch, which is, therefore, frequently found in perennial plant parts (for example, subterranean stalks called rhizomes: potatoes or ginger) or in seeds (e. g., cereals).
- Sulfur compounds:
Many sulfur compounds featuring sulfur in low oxidation state emanate a strong, rather unpleasant smell (e. g., thioles, sulphides and di- and polysulphides). As biochemicals, they are most prominent in the onion family (Alliaceae: garlic and onion), but appear also in the botanically unrelated asafetida.
Lipids are commonly known as fats if solid and as oils if liquid; there is no further difference between fat and oil besides the melting point, which reflects gradually different composition. Lipids are an efficient form to store energy, and occur, in the plant kingdom, mainly in seeds. Vegetable oils and fats are nearly exclusively composed of triglycerides,
i. e., esters of the alcohol glycerol with three molecules of fatty acids. Fatty acids are long-chain carboxylic acids, ranging in chain length from 12 (lauric acid) to 22 (behenic acid); shorter or longer chains are rarely found in significant amounts. Plants cannot synthesize fatty acids with an odd number of carbon atoms.
Examples for unsaturated fatty acids are oleic, linoleic and linolenic acid, with one, two and three C=C double bonds, respectively. Linolenic acid is essential for humans, and, in the past years, large intake of linolenic acid was considered most important in preventing a number of diseases resulting from unbalanced lipid metabolism. Yet recent studies indicate that the importance of oleic acid may have been underestimated in the past.
Besides contributing a flavour of their own, oils are most important as a cooking medium that allows various techniques of high-temperature cooking, resulting in brown, crispy and tasty surfaces. But there is another point: Since most aroma compounds dissolve more easily in fat than in water (chemist call such a behaviour lipophilic), small amounts of vegetable or animal fat tend to improve the taste of every dish, since they extract the aroma from the spice pieces. Indians like to fry their spices shortly in hot oil, which is even more effective because the high temperature increases the solubility and speed of solution.
I have tried to give etymological explanations to the names of spices wherever I was able to find some in different sources. Different sources differ amazingly in their interpretation of names, and in some cases simply no convincing derivation is known. In many cases, Greek or Latin names have (via the pharmacies of the Middle Ages) spread to all European tongues, but this makes it even harder to find the ultimate source of the name.
With respect to plants native in the Mediterranean region, we frequently find that names can be traced back to Old Greek, but not further. In some cases, early loans from some semitic tongues (e. g., Phoenician) are supposed, but in others, no connection to any known language can be constructed. This, certainly, does not imply that the Greek built these names arbitrarily, but simply indicates that the original languages are now lost. The Greeks themselves were invaders who came to the Southeast European peninsular in the second millennium B.C.; it is reasonable to suppose that they named all plants new to them by words taken from the local pre-Greek tongue. Unfortunately, we do not know anything about these pre-Greek (also called Aegean or Mediterranean) languages. Some of the plant names taken thence may be crocus (saffron), marjoram, mint, olive, rose and parsley (another example is lotus).
Another complication is caused by the phenomenon of folk etymology,
which is found in all languages: A name of no special significance to the
speaker is influenced by common word which it, by chance, resembles. For
example, English orange was borrowed from Italian arancio, but the initial vowel changed its quality, being
influenced by French or
gold, which seems a reasonable
association for a golden-yellow fruit, but is linguistically not related at
all. Folk etymology occurs also with old names that have lost their meaning
even to native speakers.
Combined effect of multiple loaning and folk etymology sometimes yield curious
results. So, English horseradish obviously has nothing to do with
horses – but still it is surprising to learn that the first element
of this name had
meant greater. In German, the plant war originally termed mehr-rettich
great-radish (German mehr being
equivalent to the related English more), which was later reinterpreted
as the homophonous meer-rettich
etymology). In English, the first element was associated with mare
female horse and the plant was therefore called horseradish (loan
After these explanations, no one will doubt that etymologies are mostly an
uncertain matter. Sometimes, many plausible theories have been ventilated by
different sources; sometimes no reasonable explanation is known. Still,
I feel that having a close look at word history give surprising insight in
early relations between cultures which seem far sundered today; for example,
we learn that mustard was brought to Central Europe by the Romans and prepared
with wine (vinum mustum,
young wine), but the German name of the plant,
Senf, goes (possibly) even back to the border area between Afganistan and Türkmenistan, thus showing
that even in the antiquity, the world was not infinitely large or unconquerable.
Maybe, in some distant future, I shall present a collection of recipes at this WWW site; but for the next time, this is not planned. There are several reasons for this decision:
First, there are more recipe sites in the internet even the most productive cook can try in his lifetime (a tiny selection of recipe sites is featured at my WWW pointer collection). There is no reason for me to further increase that superfluousness. I furthermore do not think that recipes I could offer to the net community were in some way singular or innovative to meet the concurrence.
Second, I feel sure that anyone seriously interested in any particular cooking style owns plenty of books devoted to that theme. I could probably not add anything substantial.
Third and most important, I do not feel that recipes are that crucial. Recipes are sequences of single working steps; in order to get satisfactory results, one must master these steps technically and be able to estimate their combined influence on the finished dish. To me it seems most important that my readers get the necessary knowledge to find answers to questions like: What spice fits to the dish? In which manner can I apply it? Which other ingredients does it harmonize with? When must I add it? What cooking technique (boiling, frying, deep-frying, baking, …) works best? Given these answers, all you further need is just talent of improvisation, trained taste buds and spirit of adventure (not necessarily in that order).
Fact knowledge is most important if you want to cook authentically. Correct choice of cooking fat, vegetables and spices (and of course, cooking technique) is an important prerequisite to imitate the taste of your last holidays within the limits of your own kitchen. To make such a choice easier, I have put most emphasis on background and larger context than on isolated recipes.
It should be clear, thus, that my sporadic hints on the preparation of some
famous or typical dishes do not even try to substitute real
explanations I intend to give the reader a coarse idea on a dish or a
cooking style and, maybe, to make him interested in these. If you do not try to
mix the five above ingredients (and probably get disappointed by the result),
but buy a book on Italian cuisine and read it carefully, then you have met my
As a last point, I like to take position with regard to a much-discussed question: Is it better to buy ground spices, or should you buy them as a whole and grind them yourself?
There are arguments for both sides. Industrial spice mills are not like your coffee mill – they are able to cool their content during grinding, thus preventing volatile constituents to evaporate. Furthermore, the produce a very fine powder which, by its high surface, releases its aroma quickly and efficiently. On the other side, exactly this high surface/volume ratio makes the product more susceptible to degradation during storage – either by evaporation or by reaction with oxygen.
This loss of aroma is not a purely academic problem noticed by the finest gourmets’ taste buds, but dramatically quick: Whole cloves, for instance, can be kept for years; I will have to increase the amounts slightly, but even after five years less than 50% of the essential oil is gone. Ground cloves, on the other side, will be essentially tasteless after but one year and thus unsuited for cooking at all. Storage conditions, though, will notably influence aroma stability; yet I found the simultaneous conditions cool, dry and dark difficult and not easy to combine with readiness and quick availability near the oven.
Thus, I feel ground spices only suited for large spice consume, which makes it necessary to buy fresh, sealed containers every few months. This is certainly not true in most households. Thus, I prefer whole spices in nearly all cases; grinding may then be performed with a small mortar (metal is not acceptable!) for amounts of about a tea spoon; larger quantities are conveniently treated with a coffee mill (which must not be used for coffee any more, otherwise your coffee will taste rather, ahem, unique). Such a home-made powder is not as fine as commercially ground spices, but since it is much fresher, the quality is still significantly superior.
Some spices are, because of their strong texture, difficult to grind at home. Examples are rhizomes in the ginger family (ginger, galangale and turmeric) and some other woody plant parts, e. g., cinnamon (even more cassia) and star anise. If you want to have these spices ground at all, it is probably most advantageous to buy them in powder, but in small amounts.
Some other spices are nearly always sold ground; of these, paprika is probably the most important example. Buying small quantities and using them quickly is probably the best idea. The same holds for some spice mixtures like chili powder.