The oils which give herbs their delightful aromas and flavors are volatile, i. e they’ll readily escape from leaves, stems, seeds, or other parts once these have been injured, and will then be further reduced by evaporation. Moreover, any cuts bruises or other injuries to plants result in oxidation of the injured surface by the oxygen in the air, thus also changing the aroma and flavor.
How Herbs are harvesting?
Well, one of the most important points to note in harvesting herbs for storage is to avoid injuring them as far as possible. Gather the part required gently, and the cut whole stems rather than single leaves or flowers; lay them in single layers on trays, racks, or in shallow wooden vegetable boxes, and take them into the storage area quickly, otherwise cover with dark cloth or paper. Try not to pile them up to any degree, as it does not take several minutes before even a small heap warms up, and starts the process of fermentation and decomposition. Try to keep each species separate in the tray, so that they do not contaminate each other, and pick only the quantity that can be dried in the drying area comfortably, without crowding. You need to pick herbs which are clean, free from pest or disease and not discolored or damaged in any way already. If they’re dirty, sponge them quickly and lightly with cool water and pat dry with kitchen paper.
When a Harvest Herbs?
A second point to remember for maximum flavor and oil content is the time at which to harvest herbs: the time of day, the season, and the stage of growth. During the day, the morning is best, when the dew has evaporated so that the plants are dry, but before the sun is at its most intense, i.e. the early morning when the temperature is merely warm. Choice of season depends to some extent on the part and species to be harvested, but is mostly from early summer onwards. Leaves have their greatest oil content just before the flowers open; flowers are at their best when barely opened. Seeds are collected just as they ripen, and roots dug in early mid-autumn as growth ceases and when they contain the food manufactured through a complete growing season. Well, so summer and autumn is considered see the the harvesting of some part of one herb or other every week, but there’re exceptions, and these’re well described.
The leaves are the part required for the majority of culinary herbs, but the seeds often have highly individual flavors. The flowers contribute dyes in some cases as well as perfume; roots can be eaten as a vegetable, or contain the essential medicinal constituent, and there’re instances where the stems are the important part. Sometimes it is necessary to use the entire flowering plant, but whichever part is employed, is also best described.
Herbs which are to work for their living and are not grown purely for garden decoration will be wanted for use all year round, not a difficulty in warm temperate and tropical climates. But there’re quite a number in cool temperate areas which either die down in autumn, for instance herbaceous perennials, are annuals or biennials which die completely at the end of summer. Those which are grown for their foliage and which retain it all year are not a problem, and there are some which come into leaf as early as late winter and continue until late autumn, and yet others whose top growth can be kept growing for most if not all the year with the help of a gently heated conservatory or greenhouse. But flowers and seeds are only available at certain seasons whatever the climate and roots can only be obtained at the expense of the top growth. Some form of preservation is necessary for several herbs whether it is drying or freezing, and the techniques involved from the harvest to final storage should be carefully followed for full conservation of the essential oils. France herbs are harvested and dried commercially, mostly for export when buying dried herbs. It is worth seeking out Provencal herbs since they’re more aromatic than those grown in northern regions.
In order to dry the plants with minimum loss of volatile oils they need warmth, darkness and air. Temperature should ideally be between 21 and 33 C ( 70 to 90 F) Never above 36 C (96 F) that is always slightly below body temperature. Herbs dry at different rates and one has to keep an eye on them to prevent them drying too quickly. The time will vary from two to three days to a week, depending on the part and the species. An airy place is important, so that the moisture evaporating from the herbs can be dispersed quickly and darkness is essential to prevent oxidation of the material with consequent change in flavor and oil content. The domestic airing cupboard, an attic immediately under the roof in summer, provided it does not get too hot, an oven with a low temperature setting and the door ajar, a plate warming compartment an electric dryer for washing or an outhouse with a warm air fan, are suitable drying areas provided the temperature can be maintained between the limits noted.
Material should be spread out in single layers on trays or on slatted wooden racks covered with muslin or netting and the trays or frames placed in the drying area so that they have air circulating beneath as well as on top. The shallow wooden boxes with raised corners used fort tomatoes and other vegetables or fruits such as peaches or grapes are ideal as they can be stacked on top of each other and still allow for ventilation.
Alternatively the stems roots or flowers can be tied in small bundles and hung, upside down in the case of stems and flowers from a clothes line, provided there is still good air circulation. The length of drying time varies from herb to herb and in general a good guide to completion of the process is in the state of plant material. Leaves will be brittle and crisp, and will break easily into small pieces, but should not be reduced to a powdery state when touched. Stems should break sharply if they still have a tendency to bend, they need further drying. Roots must be brittle and dry right through any softness or sponginess means incomplete drying.
Seeds are slightly tricky to harvest as the final ripening occurs very quickly and they fall off and are scattered round the parents. If a few seeds fall when the plants are tapped, then they are ready for collection. Change in color is also an indication of approaching maturity, and some also change their aroma. Seeds should be dried without any artificial heat in an airy place. The almost ripe seed heads can be hung up in paper bags so that the majority of the seeds will fall into the bag as they mature. Seeds need to be thoroughly dried before storage and this can take up to two weeks.
Some Quick Drying Methods
Some herbs can be dried in the oven in a matter of three to six hours. The oven temperature should be no more than 36 c and for sensitive herbs such as basil and chervil it should never exceed 30 c. Herbs should be placed on perforated sheets of brown paper and the oven door should be left ajar to allow moisture to escape. Check the drying herbs regularly to see that they are not overheating. Microwave ovens have also have used for herb drying. Herbs with small leaves such as rosemary and thyme take about one min while larger moist leaves like mint and basil dry in about three minutes.
Storing Dried Herbs
It is often advised that dried leaves be broken into tiny pieces before storage, but even this can deplete the content of volatile oils, and it is better to store dried material as whole leaves, or in as large pieces as possible until the time of use. Before storing, remove all the unwanted material, chaff from seeds, loose pieces of stem; use a fine-mesh sieve if necessary. If leaves have to be reduced to tea leaf size at once for making herbal teas such as chamomile or peppermint a coffee-bean grinder or the grinder attachment to an electric mixer, or just crushing them with a rolling pin, will do the job.
Dried material must be stored in the dark, so containers which exclude light completely are ideal; dark brown bottles or jars are suitable and it is worth keeping medicine bottles, and other dark colored jars which are right for size and coloring. They must also be airtight, and containers should be filled completely initially, and plain paper used to fill the space that appears in the container as the herbs are used. The herbs should not kept longer than six months or so, as even with all these precautions, they will lose most of their potency, and will begin to smell hay like after this time.
Store each herbs in a separate container, unless they are to make up, for instance, mixed herbs, houquet garni, or your own favorite mixtures for marinades or fines herbs. Label the containers at once and put the date on them. If light excluding containers cannot be found, paint the containers you do have black, or cover them with black paper, or keep the boxes or bottles in the dark, in a drawer or cupboard.
The modern alternative to drying if there’s a deep freeze available is to freeze the herbs in a variety of ways. This has the advantage that they can be done as soon as picked and the rapidity of the freezing also ensures better retention of the flavor or aroma, but it does only apply to leaves, flowers and soft stems. Sprigs of the herbs to be frozen can be put in small loose bundles in polythene bags immediately they’re cut and before they wilt. They should be labelled, the bags sealed and put straight into the freezer and there is no need to blanch them first. If they’re to be used as mixtures, as suggested earlier, they can be frozen already made up for convenience, and all can go into the casserole, marinade or other dish without thawing. Alternatively they can be chopped up while still frozen, and then used, although such herbs are not suitable for garnishing as they will have lost their crisp, fresh appearance. But herbs can be chopped up fresh and then frozen, if preferred in water contained in the ice cube making tray. Cubes can then be used separately as required, and these can also be put straight into the dish concerned. Single whole leaves or flowers can be frozen in each cube, and the cubes added to winter wine punches and cordials for decoration and flavoring.