Spearmint

Spearmint is a flowering, aromatic herb of the mint family, native to Europe, that is told apart from other mints by its almost hairless leaves. Its leaves flavour teas, salads and sauces, and the plant is also grown for its essential oil, which flavours toothpaste, chewing gum, sweets and mouthwashes.

Type

Plant

Botanical name

Mentha spicata

Other names

garden mint, lamb mint

Plant

Spearmint, Mentha spicata, also called garden mint or lamb mint, belongs to the mint family, Lamiaceae. In the wild it grows in moist fields and on the margins of ponds and lakes. It is an upright perennial that grows quickly to 30–60 cm high and wide. Its square stems root wherever they touch the ground, and the plant also spreads by underground stems, often aggressively. It has been introduced into Canada, the United States, south-eastern South America and northern Africa.

The bright green leaves are lance-shaped to oval, toothed and almost stalkless, with a wrinkled surface and a strong spearmint scent and taste. In late summer the stems end in dense spikes of small lilac, pink or white flowers. The species name spicata means "spike". Spearmint is often confused with peppermint.

Uses

Spearmint is widely used in cooking. The fresh or dried leaves and flowers go into teas, drinks, jellies, syrups, sweets, ice cream, lamb dishes and mint sauce, and the leaves are also used in salads, as a garnish and in potpourri. The plant has considerable economic value as a flavouring for chewing gum and tea and as an essential oil crop.

Spearmint oil

Spearmint oil is steam-distilled from the flowering tops of the plant, which are partly dried first. The oil may be sold as it comes from the still or rectified, that is, distilled again, to the buyer's needs. Its main constituent is carvone, in the form called l-carvone; its mirror-image form, d-carvone, is typical of caraway oil.

Natural spearmint oil is a pale olive or pale yellow, runny liquid. Its smell is very warm, slightly green and herbaceous, penetrating and powerful, much like the crushed herb. Its taste is just as warm, almost biting, spicy-herbaceous and somewhat bitter; rectified oils are less bitter and sweeter. Because carvone dissolves in water, the oil tastes surprisingly weak for so strong a smell.

The oil is used mainly to flavour toothpaste, chewing gum, sweets and mouthwashes, often to round off a peppermint flavour. In perfumery it gives a herbaceous, green note to lavender-type and jasmine fragrances, and it keeps unusually well in soap.

Safety

Spearmint is only mildly poisonous. Eating large amounts can cause vomiting and diarrhoea, and the harmful substances are in its essential oil. The plant does not cause contact dermatitis, but it can be a problem for cats, dogs and horses.

Spearmint essential oil can cause skin allergy. In Canada, licensed aromatherapy products may contain it at 1–4% for use on the skin. Because it is listed as a sensitising oil, such products must not be used on broken, irritated or sensitive skin. Products with more than 1.7% spearmint oil are not for people prone to allergic reactions, eczema or unusual skin reactions.

Products containing it

• Oral Nasal Hygiene Spray Strong (E 142)