Start with a Morning Harvest

There is a particular pleasure in walking out to the herb patch on a summer morning with a pair of scissors and coming back with more than you can possibly use fresh. Drying that surplus is one of the oldest kitchen skills there is, and it means you can be spooning your own thyme into a casserole in February while the supermarket sells you a sad little plastic packet for two pounds.

Timing matters more than technique. Cut your herbs mid-morning, once the dew has dried but before the sun has been beating down on them for hours. That is when the essential oils are at their most concentrated in the leaves. If you harvest in the heat of the afternoon, you lose aroma before the herbs even reach the kitchen. Avoid cutting on a wet day, too — damp foliage is the fastest route to mould.

Harvest just as the plants are coming into flower, or while the buds are still tight. After flowering, flavour declines noticeably in most leafy herbs. Take no more than a third of the plant at a time, and give it a fortnight to recover before you cut again.

Air-Drying in Bundles

Air-drying is the gentlest method and needs almost no equipment. It suits woody, low-moisture herbs best: rosemary, thyme, oregano, marjoram, sage, savory, bay and winter savory.

• Strip the bottom few inches of leaves so you have bare stems to tie.
• Gather five to eight stems into a loose bundle — too tight and air cannot circulate, which invites mould.
• Secure with string or a rubber band, which tightens as the stems shrink.
• Hang upside down in a dry, dark, airy spot: an airing cupboard with the door ajar, a spare bedroom, or a shed shelf out of direct sun. Light fades colour and flavour.

In a warm, dry room, bundles are usually crisp in one to two weeks. In a British summer, where humidity is often stubbornly high, it can take three. If your house is damp, a small dehumidifier in the drying room makes a real difference.

Screen-Drying Soft Herbs and Seeds

Soft-leaved herbs such as mint, lemon balm, dill, parsley and chervil tend to crush and darken if you bundle them. Lay the sprigs in a single layer on a muslin-covered cake rack, a clean window screen or a sheet of baking parchment stretched over a frame. Turn them gently every day or two and keep them out of strong light. Expect three to seven days.

For seed heads — dill, fennel, coriander, caraway — hang the stems upside down inside a paper bag with a few holes punched in the side. As the seeds dry, they drop neatly into the bag instead of onto your floor.

Speeding Things Up with a Cool Oven

If the weather has turned muggy, or you simply want the job done, a cool oven works beautifully — provided you resist the temptation to turn up the heat. High temperatures drive off the oils you are trying to preserve.

• Set the oven to its lowest setting, ideally 40–50°C. If it will not go that low, prop the door open with a wooden spoon.
• Spread the herbs in a single layer on a lined baking tray.
• Dry for two to four hours, checking every 30 minutes.
• Leaves are ready when they crumble easily between your fingers and the stems snap rather than bend.

A dedicated dehydrator runs at the same low temperature and gives more even results, particularly useful if you are processing a big crop of oregano at once. A microwave works for tiny quantities but is fiddly and easy to scorch — I would rather not bother.

Know What Freezes Better Than It Dries

Not every herb is worth drying. Basil, tarragon, chives, chervil and parsley lose much of their character when dried, turning grassy and dull. Chop them finely, pack into ice cube trays, top with water or olive oil, and freeze. You will thank yourself when a winter soup needs a lift.

Mint and lemon balm dry acceptably but are far better frozen for teas. Rosemary, thyme, oregano, sage, bay and dill are the stars of the drying rack — their oils hold up well over months.

Storing Your Dried Herbs Properly

The most common mistake is jarring herbs before they are fully dry. Any lingering moisture will turn the whole batch musty within weeks. Test by bending a stem: it should snap cleanly, not flex like a piece of wire.

Leave the leaves whole rather than crushing them for storage — crumbled herbs lose aroma far faster. Strip leaves from woody stems over a bowl, discarding anything brown or dusty, and fill small airtight jars. Glass with a rubber seal is ideal; keep them in a dark cupboard away from the cooker.

• Label every jar with the herb name and the month and year you dried it.
• Store in small quantities so you are not opening one big jar all winter.
• Use within 12 months for best flavour, and crush or rub the leaves between your palms just before adding them to the pot.

A final tip: check your jars a week after filling. If condensation appears on the inside of the glass, tip everything back onto a tray and dry it again. Better a small faff in August than a cupboard full of wasted summer.