How to dry herbs: times and temperatures

Drying herbs at home It allows you to preserve basil, sage, rosemary, thyme, oregano, mint and many other herbs whilst retaining as much of their fragrance, colour and flavour as possible.

The key point is to work on low temperature, generally around 40 °C, and only stop the drying process once the leaves and stems have completely lost all their moisture.

With a domestic food dehydrator It is possible to control the temperature and ventilation throughout the process, thereby avoiding dependence on environmental conditions, as is the case with air-drying.

So let’s take a look how to prepare the herbs, what temperature to use, how long it takes and how to store them once they are dried.

Why dry herbs at home?

Fresh herbs do not keep for very long. Basil, parsley, mint and other delicate varieties can quickly lose their texture and aroma; rosemary, sage, thyme and oregano last longer, but we often harvest more than we can use straight away.

Drying makes it possible to to store the harvest and use it throughout the year, significantly reducing the volume and weight of the plants.

It is particularly useful for anyone who grows herbs in their vegetable garden or on their balcony: rather than letting part of the harvest go to waste, you can turn it into a small supply of dried herbs for seasoning, herbal teas, infusions and cooking.

Unlike simply leaving it out in the open, using a dehydrator also allows you to work under more controlled conditions, adjusting the temperature according to how delicate the product is.

When to harvest herbs for drying

Proper drying starts with the raw material.

Pick the herbs clean and dry, preferably in the morning, once the night-time damp has evaporated and before the hottest part of the day.

Where possible, avoid picking them immediately after it has rained: a greater amount of surface water slows down the drying process.

The stage of the plant’s growth can also influence its flavour profile. For many species, it is best to harvest before full bloom, when the leaves are still tender and intensely fragrant.

Remove any yellowed, damaged or stained leaves before you start.

Should you wash herbs before drying them?

It depends on where it comes from.

If the herbs have been picked from a vegetable garden or from clean pots and are free from soil or impurities, a thorough check may be sufficient.

If, however, you need to wash them, carry out a quick and gentle rinse, then carefully remove the surface water.

You can pat them dry with a clean cloth or gently spin-dry them in a salad spinner.

Before placing them in the dryer, they must be completely dry on the outside: Water left on the leaves unnecessarily increases the time needed to complete the process.

Rosemary, thyme and other hardy plants are easy to handle; basil, mint, lemon balm and parsley, on the other hand, require a more delicate touch.

How to dry herbs

There are three main methods: air-drying, oven-drying and using a dryer.

Drying herbs in the open air

That’s the traditional system.

The hardier herbs can be picked in small bunches and hung up in a room dry, well-ventilated and protected from direct light.

It works particularly well with rosemary, thyme, oregano, sage and other herbs with low water content.

The main limitation is control: temperature and humidity depend on the environment, and drying times can vary considerably. In damp conditions, drying becomes slower and less uniform.

Drying herbs in the oven

A domestic oven can be used, but it is less suitable when you want to work at very low temperatures.

In fact, many ovens have a minimum temperature of 50–60 °C or higher, and temperature control may be less precise than that of a dryer.

For particularly aromatic plants, where it is important to limit exposure to heat, this is therefore not the easiest solution to manage.

Drying herbs in a dehydrator

L’food dehydrator It allows you to set low temperatures and maintain constant ventilation throughout the process.

With Biosec, the horizontal airflow passes through the various baskets simultaneously, whilst the Dryset Pro electronic system allows you to choose between automatic programmes and manual temperature settings.

Arrange the herbs on the racks to form a thin layer, without pressing them down. Air must be able to circulate freely between the leaves and twigs.

For small harvests of herbs grown on the balcony or in the vegetable patch, a compact model such as Biosec Domus B5, fitted with 5 baskets.

If, on the other hand, you harvest larger quantities of sage, rosemary, basil or other herbs at the same time, the 10 baskets of Biosec Domus B10 They offer a larger surface area whilst retaining the same Dryset Pro system and the same Biosec airflow.

The choice between the two therefore depends above all on the the quantity of product you wish to dry at the same time.

Temperature for drying herbs

When it comes to herbs, it is best to use moderate temperatures, around 40 °C.

With Biosec, a particularly suitable solution is P3 BioCrudist: the programme reaches 42 °C in the first two hours and then continues at 40 °C.

The programme does not have a set duration: it should be stopped once the product has reached the desired level of dryness.

You can see the temperatures, duration and ventilation in the full table of Dryset Pro programmes by Biosec.

Alternatively, you can use the manual programme T3 at 40 °C.

Low temperatures are particularly beneficial for delicate plants rich in volatile aromatic compounds, such as basil, mint, lemon balm and parsley.

How long does it take to dry herbs?

There is no single time that is the same for all herbs.

As a starting point:

• rosemary and thyme: approximately 12–15 hours;
• sage and oregano: check gradually, taking into account the size and quantity of the leaves;
• basil: requires special care to prevent discolouration;
• mint and lemon balm: also check the petioles and veins;
• parsley: Check that even the thickest parts are completely dry.

These times are necessarily approximate. The load size, leaf size, initial moisture content and environmental conditions all affect the actual duration.

That is why Don’t rely solely on the timer.

The leaves are ready when they feel dry and brittle to the touch. The thinnest twigs should snap rather than bend.

If any part of the plant is still soft or damp, carry on drying it.

How to dry basil, rosemary, sage and mint

Each plant has slightly different characteristics.

Basil

It is one of the most delicate herbs. Use healthy, dry leaves, arrange them without overlapping them, and keep the temperature low, at around 40 °C.

Check it regularly during the process.

Rosemary

It’s much more durable. You can dry small twigs whole and then separate the needles from the stems.

It is ready when the leaves are completely dry and the twig snaps easily.

Sage

Arrange the leaves individually on the trays, taking care not to overlap them. Larger, meatier leaves may take longer to cook than thyme and rosemary.

Mint and lemon balm

Handle them gently and cook them at a low temperature.

Pay particular attention to the petiole and the thicker veins: the surface of the leaf may already look dry, whilst these parts still retain moisture.

Thyme and oregano

They are among the easiest herbs to dry. They can also be dried in small sprigs and separated from the stems after drying.

Mistakes to avoid

The first mistake is pile the herbs too high or pack them too tightly into the baskets. Good air circulation helps ensure more even drying.

The second is to use excessively high temperatures in an attempt to reduce processing times.

The third step is to place the herbs in the containers whilst they still have some residual moisture.

Finally, avoid prolonged exposure to light whilst storing the product: the colour and flavour profile are best preserved in a cool, dark cupboard.

How to store dried herbs

Once the herbs have finished drying, store them in clean, dry and tightly sealed containers, preferably made of glass.

Store them away from light, heat and moisture.

It is preferable keep the leaves and twigs as whole as possible and crumble them just before use. This way, the surface area exposed to the air is minimised and the aroma is released mainly when needed.

Label the containers, stating the type of herb and the date it was dried.

To find out more about this stage, you can also read the guide on how to store dried food properly.

Which dehydrator should you choose for herbs?

For domestic use, you don’t necessarily need a very large tumble dryer: what matters most is the area required to spread the herbs out without them overlapping.

For this reason, the Biosec Domus B5 may be suitable for occasional harvesting and small quantities, whilst the Domus B10 is more suitable when harvesting large quantities of herbs at the same time or if you have a productive vegetable garden.

Those who prefer stainless steel baskets and tunnels may instead opt for the Biosec De Luxe models from the domestic range, which use the same Dryset Pro electronic system.

If, on the other hand, the drying of aromatic plants forms part of an agricultural, herbal or commercial activity, the requirements and volumes change completely: Tauro devotes a specific in-depth section to solutions for herb growers, medicinal plants and herbal teas.

Drying herbs properly means, above all, Start with good-quality raw ingredients, cook at a gentle temperature and wait until all the moisture has really evaporated. With these tips, produce from your vegetable garden or balcony can be used in cooking well beyond the season in which it was harvested.