Drying and Storing Herbs: The Homegrown Herb Rack, Done Properly

A well-stocked herb rack is one of the quiet pleasures of growing your own. A single summer's worth of sage, thyme and oregano, dried and jarred, will season your cooking right through to the following spring, and it costs nothing but a bit of timing and attention. The trick is not complicated, but it is exact: you are racing the leaves' own moisture. Get the water out quickly enough and you lock in colour, scent and flavour. Let it linger and the same leaves go brown, musty and, in a damp kitchen, mouldy.

This guide covers the whole business, from knowing when to cut to keeping the jars fresh: when to harvest, which herbs dry easily and which fight you, the four drying methods worth knowing, how to store the results, and when freezing beats drying altogether. There is one genuine food-safety point at the end, about herbs and garlic in oil, that is worth reading even if you skim the rest.

When to harvest for drying

Timing does more for the final flavour than any drying method you choose, because you cannot dry in more oils than the leaf had when you cut it. Aim for mid-morning: once the dew has dried off the foliage but before the sun climbs to its midday heat. That is the window when the aromatic oils in the leaves are at their most concentrated.

Beyond the time of day, the stage of growth matters, and it splits along the same soft-versus-woody line that runs through the whole subject.

• Most leafy herbs, cut before flowering. For the likes of basil, parsley, coriander, mint and chives, the leaves are freshest and least bitter before the plant flowers, and regular cutting before flowering also keeps the plant bushy and productive rather than running to seed.
• Woody herbs, cut as they start to flower. Rosemary, thyme and sage carry their strongest oils just as they begin to come into flower, so that is the moment to gather them for drying.

Which herbs dry well, and which need speed

Herbs fall into two broad camps, and knowing which camp you are dealing with tells you which method to reach for.

Herb type	Examples	Best approach
Sturdy and woody, low moisture	Sage, thyme, rosemary, bay, oregano, savory	Air-dry easily, or any method
Leafy but reasonably dry	Parsley, coriander	Air-dry, though a dehydrator or low oven is quicker and greener
Tender and high moisture	Basil, mint, tarragon, chives, lemon balm	Dry fast (dehydrator, oven, microwave) or, better, freeze

The reason for the split is simply water content. Sturdy, resinous herbs hold little moisture and dry cleanly in the open air. Tender herbs are packed with water in their soft leaves, and left to dry slowly they tend to go brown and can mould before they are done. For those, either speed the drying up or skip drying and freeze them instead, which usually keeps their flavour better anyway.

The four ways to dry herbs

Air-drying: the classic, and the easiest for woody herbs

For sage, thyme, rosemary, bay and the other sturdy herbs, nothing beats hanging them up. Gather a few sprigs into a small, loose bunch, tie the stems, and hang it upside down somewhere warm, dry, dark and well ventilated. An airing cupboard is close to ideal. Keep the bunches small so air moves freely through them, and expect them to be ready in roughly five to ten days depending on the herb and the conditions.

The one rule people get wrong is light. Dry herbs in the dark, not on a sunny windowsill, because direct sunlight bleaches the colour and drives off the very oils you are trying to keep. A dim, airy room or cupboard is far better than a bright one.

Oven: low, slow and watched

An oven works when the weather is against you or you want herbs dry in a day rather than a week, though it is easy to scorch them. Spread the leaves in a single layer on a lined tray and use the very lowest setting your oven will hold, leaving the door slightly ajar if you can to let moisture escape. As an approximate guide, gentle warmth of around 35 to 43°C suits the job, but ovens vary and these figures are indicative rather than exact, so let the herbs, not the dial, tell you when they are done. Check every 15 to 20 minutes and pull them out the moment they are crisp.

Dehydrator: the most controllable method

A dehydrator is the neatest tool for the job, giving steady low heat and airflow with little to scorch. Lay the herbs in a single layer across the trays and run it low. As a rough range, somewhere around 35 to 46°C works well, edging up towards 52°C only if your kitchen is humid, and most herbs are done in about one to four hours. Again, treat those temperatures as approximate starting points rather than precise UK settings, since they come from drying guidance abroad and every machine differs. If you are weighing up a dehydrator for herbs and much else besides, our guide to dehydrating food walks through choosing and using one in more detail.

Microwave: only for small batches

The microwave is a quick fix for a handful of leaves, not a way to process a harvest. Lay the leaves between two sheets of plain kitchen paper, no more than a cup or so at a time, and heat on high in short bursts of a minute to two minutes, stirring or turning them every 30 seconds so they dry evenly rather than cook. Finish them off at room temperature rather than pushing the microwave to crisp them fully. Never do more than one or two cups at once, and watch closely, because dry herbs can catch quickly.

Storing dried herbs so they last

Getting the herbs dry is only half the job. Stored badly, they fade fast; stored well, they hold their flavour for months.

Storing dried herbs, step by step

1. 1

   Cool completely

   Let the herbs cool to room temperature before you jar them, so no residual warmth turns to condensation inside the container.

2. 2

   Keep leaves whole

   Store leaves whole rather than crushed. Whole leaves hold on to their aromatic oils far longer, so only crumble them just before cooking.

3. 3

   Use airtight glass or tin

   Pack them into clean, dry, airtight glass jars or tins. Airtight is what keeps moisture and stale air out.

4. 4

   Cool, dark and dry

   Store the jars somewhere cool, dark and dry, away from the heat and steam of the hob and out of direct light, which both drive off flavour.

5. 5

   Label and date

   Label every jar with the herb and the date so you know what you have and how old it is.

6. 6

   Check within a few days

   Glance at the jars a few days later. Any condensation means the herbs were not fully dry, so tip them out and dry them further before they mould.

Kept this way, most dried herbs are at their best for around six to twelve months. They rarely become unsafe, they simply lose their punch, so a jar that has gone faint is a signal to use more of it or replace it next season. If you are short of cool cupboard space, you can also store dried herbs in the freezer, which keeps them fresh even longer.

Herbs grown for their seeds, such as dill, coriander and caraway, are handled slightly differently. Let the seed heads dry fully, then rub the seeds free and blow or winnow off the papery chaff. Store the seeds whole, as they keep their flavour longest that way, and grind them only when you need them.

Freezing herbs: often better than drying

For the soft, tender herbs, freezing usually preserves far more of the fresh, green flavour than drying ever will. Frozen herbs go limp when they thaw, so they are not for garnishing a plate, but they are excellent stirred into anything cooked: soups, stews, sauces and sautés.

The simplest method is the ice-cube tray. Chop the herbs, drop about a tablespoon into each section, top up with water, and freeze. Once solid, pop the cubes into a labelled and dated freezer bag so you can drop one straight into a pan as you cook. Frozen herbs are best used within about four to six months.

You can also freeze herbs in oil rather than water, which holds the colour especially well and suits basil in particular. That works, but only under strict conditions, which brings us to the one real safety point in all of this.

The one safety rule: herbs and garlic in oil

Home-made herb-in-oil and garlic-in-oil are genuinely risky if stored wrongly, and this is worth taking seriously rather than treating as fussiness.

Before you fill the herb rack: a quick checklist

1. Did you cut the herbs mid-morning, on a dry day, at the right stage of growth for that plant?
2. Have you matched the method to the herb, air-drying the sturdy ones and drying the tender ones fast or freezing them?
3. Are the herbs truly crisp, crumbling and snapping, before they go anywhere near a jar?
4. Are they in airtight glass or tin, whole-leaf, labelled, dated, and kept cool, dark and dry?
5. For soft herbs you would rather freeze, have you bagged and dated the cubes?
6. Any oil involved: is it going straight in the freezer, or the fridge at 4°C or below for no more than about a week, and never a cupboard?

Herbs and food-safety guidance are updated from time to time, so for the botulism point in particular it is worth confirming the current advice with the Food Standards Agency or NHS, and checking your own herbs against the crisp-and-snap test rather than a fixed drying time.