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.
Drying Herbs
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.
Freezing Herbs
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.