Rue is a pungent, intensely bitter Mediterranean herb once common in Roman cooking and now used sparingly in grappa, Ethiopian coffee and a few dishes. Its sap can burn skin in sunlight.
What it is¶
Rue is a small, woody, evergreen shrub with finely divided, blue-green leaves and clusters of mustard-yellow flowers in summer. Crush a leaf and it gives off a powerful, musky, almost rank smell that people tend either to find intriguing or to dislike on the spot; the species name graveolens means "strong-smelling".
In the kitchen it is one of the most bitter of all herbs, and it is used in tiny amounts: a single small leaf, finely chopped, or a sprig left to infuse and then removed. Beyond Europe, the closely related fringed rue (Ruta chalepensis), with feathery-edged petals, is the rue of the Middle East, North Africa and Ethiopia.
Rue belongs to the citrus family, which is why its oil carries a faint orange-peel note beneath the bitterness. It also shares with limes and bergamot the ability to cause sun-triggered skin burns (see Health and safety below). Anyone growing it should know this before pruning it in shorts on a sunny day.
Origins and history¶
Rue was a mainstream flavouring in the ancient Mediterranean. The Roman cookery collection attributed to Apicius, compiled in the late Roman period, calls for ruta over and over, both fresh leaves and seeds, in sauces for fish, meat and vegetables, often alongside lovage, cumin, honey and fish sauce. Pliny the Elder discussed it at length as a medicinal plant. See spices in the ancient world.
In medieval and early modern Europe rue was a staple of physic and monastery gardens and the herbals, valued as a strewing herb and a supposed protection against plague, poison and the evil eye. These uses are folklore. Its English nickname "herb of grace" appears in Hamlet, where Ophelia hands it out: "there's rue for you; and here's some for me: we may call it herb of grace o' Sundays."
As tastes moved away from bitter, heavily spiced food, rue largely vanished from European cooking. It survives in a few places: in northern Italy, in the Balkans, and in Ethiopia, where it is still widely grown and used.
Flavour and aroma¶
Rue is sharply and lingeringly bitter, with a musky, resinous, slightly fruity aroma. Some find a hint of blue cheese or orange peel in it. Cooking softens the bitterness a little but does not tame it, and too much will make a dish acrid and medicinal.
Fringed rue (R. chalepensis) is broadly similar, and often described as slightly less harsh.
In the kitchen¶
Think of rue as a bittering agent rather than a leafy herb. The golden rule is one small leaf at a time.
- Grappa alla ruta. The best-known modern use. A single sprig of rue is put into a bottle of grappa and left for a few weeks, giving a pale green tinge and a bitter, herbal edge. It is traditional in Veneto, Friuli and other parts of northern Italy, and is drunk as a digestif. Remove the sprig after a month or so if the flavour becomes too strong.
- Ethiopian coffee. In Ethiopia and Eritrea, rue is called tena adam ("health of Adam"). A small sprig is often served with, or dropped into, a cup of freshly brewed coffee during the coffee ceremony. The dried seeds are also used in some spice mixtures and in the preparation of spiced butter (niter kibbeh); some versions of berbere include them. See ethiopian cuisine.
- Eggs and cheese. A few finely chopped leaves can go into scrambled eggs, a salad dressing or a soft cheese, in the manner of a bitter herb such as sorrel or dandelion.
- Roman-style sauces. Cooks recreating Apician recipes use a pinch of chopped rue with lovage, cumin, black pepper, honey and vinegar.
- Meat and game. A leaf or two in a marinade for lamb or game is a traditional Middle Eastern and Mediterranean use.
⚠️ Handle with care
Wear gloves when picking or chopping rue, and wash your hands and knife afterwards. The sap is the problem, not eating a leaf. See below.
Buying and storing¶
Rue is almost never sold fresh; cooks who use it grow it. Cut sprigs keep for a few days in a glass of water or wrapped in the fridge. The leaves can be air-dried and kept in a sealed jar for up to a year, although they lose some of their aroma. Ethiopian grocers sometimes sell dried rue seed. See drying herbs.
Substitutes¶
Nothing has quite the same musky bitterness. A little sage or rosemary gives a resinous note; mugwort or a few dandelion leaves supply bitterness. In a grappa infusion, a strip of lemon peel and a juniper berry or two make a pleasant, different drink.
Pairs well with¶
Grappa and other spirits, coffee, eggs, soft cheese, lamb and game, olives, garlic, lovage, cumin, black pepper, honey and vinegar.
Growing your own¶
Rue is easy to grow in a sunny spot with poor, free-draining soil, and it is hardy in most of the UK. The blue-leaved cultivar 'Jackman's Blue' is compact and grown widely as an ornamental.
- Starting. Sow seed under cover in spring, or buy a plant. Take semi-ripe cuttings in late summer.
- Position. Full sun and good drainage; it tolerates drought and chalky soil, and dislikes winter wet.
- Pruning. Cut back in spring to keep the plant compact and bushy, removing old flowered stems. Always wear gloves and long sleeves, and prune on a dull day or in the evening.
- Placement. Plant it away from paths, children's play areas and anywhere people brush past it in summer.
Health and safety¶
Rue needs to be treated with more caution than almost any other culinary herb.
- Phototoxic sap. Rue contains furanocoumarins (including psoralen, bergapten and xanthotoxin). If sap from the leaves gets on the skin and the skin is then exposed to sunlight, it can cause phytophotodermatitis: redness, painful blistering and burns that may appear a day or so later, sometimes severe enough to need medical treatment. The affected skin can stay darkly stained for months. Gardeners and children playing near rue are the usual victims. Wear gloves and long sleeves, work on a dull day, and wash any exposed skin with soap and water promptly. If blisters appear, keep the area out of the sun and seek medical advice.
- Pregnancy. Rue has a long history of use as an abortifacient, and large doses have caused severe poisoning and deaths. Do not eat rue, drink rue infusions or use rue oil if pregnant or trying to conceive.
- Quantity. A leaf in a dish or a sprig in a bottle of grappa is the traditional scale of culinary use. Large amounts, strong teas and the essential oil can cause vomiting, liver and kidney damage and other serious effects, and should be avoided entirely.
- Medicines and children. Keep rue out of reach of children, and seek advice before using it if you take prescription medicines.