Oregano

• riganiρίγανη

  Greek

• origano

  Italian

• orégano

  Spanish

• orégano

  Spanish — Mexico

  In Mexico the word names Lippia graveolens, an unrelated plant in the verbena family. A recipe translated from Mexican Spanish and made with Mediterranean oregano loses the citric, resinous character the dish was built on.

• kekik

  Turkish

  Kekik covers oregano and thyme together, and Turkish markets sell several species under it.

• za'atar

  Arabic

  In the Levant za'atar names a wild Origanum or Thymbra species and also the sesame-and-sumac blend made with it. It is not interchangeable with a jar of Italian oregano.

Assertive, slightly bitter, faintly numbing at the back of the tongue, with a resinous persistence that outlasts almost anything else in a tomato sauce. Greek oregano is the most pungent of the commercial types; Italian is softer and closer to marjoram.

Pungent, warm and distinctly medicinal — the smell of a pizzeria, and underneath it something closer to thyme than to any soft herb. Rubbing dried oregano between the palms before it goes in is not a flourish; it breaks the leaf and releases oil that would otherwise stay put.

A grey-green to olive, never bright. Vivid green dried oregano has usually been dried too fast or is not entirely oregano.

Small brittle flakes that stay visible in a finished dish and never fully soften. In a long-cooked sauce this does not matter; scattered raw on a salad it is noticeable and not always wanted.

• Carvacrol — The dominant phenol in Greek oregano and the source of the warm medicinal pungency. Carvacrol content is essentially what separates a good oregano from a dull one.(what carvacrol is)
• Thymol — The same compound that defines thyme, present here in smaller proportion. It is why oregano and thyme smell like cousins.(what thymol is)
• p-Cymene and γ-terpinene — Biosynthetic precursors of carvacrol and thymol, contributing a woody, slightly citric background.(what p-cymene is, what γ-terpinene is)
• Sabinene hydrate — Higher in Italian types and in marjoram; the sweeter, softer note that distinguishes them from the Greek plant.

Rub it between your palms as it goes into the pan — the leaf holds its oil until the cell walls break, and this is the single cheapest improvement available to anyone cooking with dried oregano. Add it early to anything simmered, because the phenols are heat-stable and want time to extract into fat and liquid. Add it late, or raw, to dressings and finished dishes where the sharper top notes are the point. Bloom it in oil if the dish has a fat phase; the flavour compounds are fat-soluble and will distribute rather than sit on top.

The defining herb of southern Italian and Greek cooking and, through pizza, one of the most widely used dried seasonings in the world. It goes into tomato sauces, onto grilled meat and fish, into marinades and dressings, through bean and vegetable dishes, and into a long list of blends — Italian seasoning, pizza seasoning, Cajun and Creole mixtures, taco and fajita seasonings, chilli powder, za'atar. Mexican oregano does a parallel job in pozole, adobos and chilli, alongside cumin and dried chilli rather than tomato and olive oil.

• grinding — Rubbing dried leaf between the palms ruptures the remaining cell structure and releases oil that an unbroken flake holds onto. It measurably changes what reaches the dish and costs two seconds.
• boiling — Oregano is unusual among leaf herbs in tolerating and rewarding long cooking. The phenols are relatively heat-stable and extract into the fat and liquid of a sauce over an hour rather than being driven off in ten minutes.
• blooming — Carvacrol and thymol are fat-soluble, so a few seconds in warm oil at the start distributes oregano through a sauce far more evenly than sprinkling it on top.
• toasting — Dry heat scorches the leaf quickly and turns the medicinal note acrid. Oregano is bloomed in fat, not toasted dry.

Crush a pinch hard between finger and thumb and smell immediately. Live oregano gives a sharp medicinal hit; dead oregano smells of hay and dust, and no amount of it will season a sauce. This is the herb people most often keep for a decade without noticing it has stopped working, because it still looks exactly the same.

• A hay or tea smell rather than a medicinal one
• Brown rather than grey-green
• No aroma at all when crushed hard

• Volatilisation of carvacrol, thymol and the terpene fraction
• Fading from grey-green towards brown
• Oxidation to a flat hay-like character

Buy rubbed leaf, always. Ground oregano fades faster, cannot be judged by eye, and gives up the one advantage the dried herb has over the fresh one, which is that it keeps. The more consequential decision is not whole against ground but Mediterranean against Mexican: those are two plants, and if a recipe comes from Mexico or the American Southwest the Mexican one is the ingredient it means.

• Rubbed leaf rather than fine flake — fragments are harder to adulterate visibly and harder to judge.
• A stated origin, and preferably a stated species. Greek and Turkish oregano are usually the most pungent.
• A sharp medicinal smell on crushing a pinch in the shop if you can, and immediately on opening if you cannot.
• Grey-green rather than either brown or artificially bright.

Commercial grading turns on leaf-to-stem ratio, colour, volatile oil content and freedom from foreign matter. Greek oregano — usually Origanum vulgare subsp. hirtum — carries the highest carvacrol and is priced accordingly; Turkish material is frequently Origanum onites and is the volume product in most markets.

Lamiaceae

A hardy perennial of Mediterranean hillsides, growing to about half a metre, with small oval leaves and clusters of tiny white or pink flowers. It is a poor plant in rich soil and a good one on dry stony ground, where the essential oil concentrates.

The Mediterranean and western Asia, where Origanum species grow wild across the whole basin.

• Turkey — major producer. The dominant exporter of dried oregano, much of it wild-gathered or semi-cultivated Origanum onites.
• Greece — major producer. The origin of the high-carvacrol Greek oregano that most cooks regard as the best.
• Mexico — major producer. Of Lippia graveolens, the other oregano — a different plant supplying a different market.
• Albania — notable producer
• Egypt — notable producer

Cut at or just before flowering, when essential oil content peaks. This is the practical reason oregano and its relatives are harvested to a calendar rather than picked as needed.

1. Cutting — Whole stems cut at the onset of flowering.Why: Oil content is highest at this point in the season.
2. Drying — Air-dried in shade or in low-temperature forced air, traditionally hung in bunches.Why: Shade preserves the green colour and limits volatile loss; high heat drives off the carvacrol that is the point of the crop.
3. Rubbing and sieving — Dried leaf is rubbed from the stems and sieved to separate leaf from woody stalk.Why: Stem contributes bulk and no aroma; the proportion of stem left in is a principal grading criterion.

Graded on the proportion of leaf to stem, on colour, on volatile oil content and on freedom from foreign matter. Carvacrol content is the underlying quality measure and is rarely stated on a retail packet.

Oregano has been among the more frequently adulterated dried herbs in retail surveys, with olive, myrtle, sumac and cistus leaf reported as bulking agents. The economics are obvious: the product is a green flake, the adulterants are also green flakes, and nobody can tell by looking. Buying rubbed leaf rather than fine flake, and from a supplier who names an origin, is the practical defence.

Grown as a perennial and cut two or three times a season. A substantial proportion of commercial oregano, particularly Turkish, is gathered from wild or semi-managed hillside stands rather than sown.

Hot, dry and stony. Oil content rises with heat, drought and poor soil, which is why hillside oregano is more aromatic than the same species grown well-fed and watered. A cook who grows oregano in a rich border and finds it bland has not done anything wrong except be kind to it.

Origanum has been gathered around the Mediterranean since antiquity and appears in Greek and Roman sources as both a seasoning and a medicinal plant. Its modern global ubiquity, though, is a twentieth-century story and an American one: oregano was a minor herb in the English-speaking world until soldiers returning from Italy after the Second World War created a demand for the flavour of the pizza they had eaten there. United States imports rose sharply through the late 1940s and 1950s, and oregano has been the pizza herb ever since.

Never a monopoly commodity — it grows across the whole Mediterranean basin and was locally available throughout the era when tropical spices were not. Turkey and Greece dominate the modern export trade in the Mediterranean species, and Mexico supplies the unrelated plant that shares the name.

Origanum species have a long medicinal record around the Mediterranean, and oregano oil is sold today on antimicrobial claims. SpiceHQ records the tradition and makes no health claim: carvacrol has demonstrable antimicrobial activity in laboratory conditions, and that is a fact about a compound in a dish rather than about a person.