Drying Herbs at Peak: Timing, Method, Jars

August is the peak and the deadline at the same time. The herbs are at their strongest, several are about to flower and change, and every one of them is more than the kitchen can use fresh.

Drying is the way to carry that forward, and it is a simple process with three places to go wrong: cutting at the wrong moment, drying too slowly or too hot, and storing before it is actually dry.

Cut just before flowering, mid-morning

The concentration of aromatic oils peaks just before a plant flowers and drops once it commits to seed. So the cut for drying is earlier than the cut you would make for the kitchen — you are harvesting a plant at its strongest rather than at its most convenient.

Mid-morning, after the dew has dried and before the day’s heat. Wet material dries slowly and unevenly, which is the origin of most mouldy batches; heat-stressed afternoon material has already lost some of what you are trying to keep.

Cut whole stems rather than picking leaves. Stems are easier to hang, easier to handle, and the leaves strip off cleanly once dry.

Three methods, and when each is right

Hanging in bunches. Small bundles — a loose handful, no more — tied at the stems, hung upside down somewhere warm, airy and dark. Free, needs no equipment, and works well for anything with a decent stem: mint, oregano, thyme, sage, marjoram.

The failure mode is bunches too thick. The middle stays damp while the outside dries, and you find out weeks later. If a bundle feels dense in the hand, halve it.

Flat on racks or screens. Better for large-leaved and high-moisture herbs — basil especially, which is thick-leaved and prone to going black when hung. Single layer, airflow underneath, turned once or twice.

A dehydrator. The most reliable and the fastest, and the one that removes weather from the equation entirely. Use the lowest setting your machine has. Heat is the enemy of aroma; you are trying to remove water, not cook.

The test, and the two-day wait

Leaves crumble rather than fold. Stems snap rather than bend. That is the whole test, and it is mechanical rather than a matter of judgement.

Then — the step almost everyone skips — jar it and check it two days later. If any condensation appears on the inside of the glass, it was not dry. Tip it back out, dry it further, and jar it again. Two days of patience against a whole jar lost is not a difficult trade, but it only works if you actually look.

Storing it so it lasts

Whole leaves, not crushed. Crushing ruptures the oil cells, and a pre-crushed jar loses strength in a few months where whole leaves hold most of it for a year. Crush in your hand as you use it.

Airtight glass, in the dark. Labelled with the plant and the year — the year is what tells you, next August, whether last year’s jar is worth keeping or whether it is time to replace it with fresh.

The record

That last column is the one that improves your drying. Two seasons of it and you will know whether the rack really did beat the bunches for basil in your climate, and whether the batch you rushed in humid weather was noticeably worse. It also tells you the only quantity that matters for planning: how much of each herb this household actually gets through in a year — which is almost always less than you dry, for two or three of them, and more for one.

Herb Helix has the harvest and drying pages ruled for this, per plant and per batch. If your work carries on into preparations rather than the kitchen, Plant Apothecary picks up from there.

This week

Walk the herb bed and find what is about to flower. That is this week’s drying, whether or not you had planned to do any.

Cut mid-morning, bundle loosely, hang in the dark. Then check in two days after jarring — that is the habit that saves batches.

— Hadley