Preserving Herbs
The most commonly used methods for preserving herbs for storage are air drying, heat drying and freezing. They may also successfully be used to flavour oils or vinegars. Whichever method you use, always ensure that the herbs are fresh and clean; wash the stems in cold running water and then drain them thoroughly on kitchen paper. However, make sure that they are thoroughly dry before preserving, or moulds may develop.
Air Drying
The easiest way to dry herbs is to allow the leaves or entire stems to air dry at room temperature. Gather together a bunch of washed (and dried) young leaves and tender stems, tie with string and hang them upside down in a well-ventilated, dark place, such as an airing cupboard, for about two to four weeks. Once the leaves are dry, strip them from the stalks and store them in dark glass jars.
Microwave Drying
An ordinary microwave oven may be used for quicker drying of herbs. However, although drying with heat is faster, if over-heated, much of the flavour, oils, and colour of the herbs can be lost.
To dry using a microwave oven, simply place washed sprigs or leaves in a single layer between two pieces of kitchen paper. Microwave them on high for one to three minutes, checking and turning them over every 30 seconds. Cool and test if the herbs are dry and brittle, and then continue microwaving for 30-second intervals until the herbs crumble easily.
After drying, store herbs in a dark glass jar in a cool place - light and heat will quickly destroy the quality of herbs.
Drying Seedheads
Place seedheads on stalks in a paper bag and hang them upside down so that the seeds fall into the bag as they dry. Keep them in a warm, dry place to ripen; when dry, remove the seeds and store them. Alternatively, place seedheads on a drying tray for five or six days, after which time he seeds should fall fairly easily from the heads. Remove the chaff, and allow the seeds to continue to dry for another week, stirring them frequently. Store seeds in airtight jars after complete drying.
Drying Roots
Wash and dry roots thoroughly, and then peel, chop or slice them before spreading them in thin layers on absorbent paper. Dry them in a warm airing cupboard until brittle; this may take several weeks. When dry, the root piece should snap when you bend it. Crush or grind the roots before storing.
Freezing
Many soft-leaved herbs can be successfully frozen, retaining a better freshness and colour after being thawed than if dried. For short-term storage, simply place washed herbs in airtight freezer bags and freeze. For longer-term storage, blanch them quickly in boiling water before cooling them in iced water. Drain thoroughly, pat dry and put them in packages. Label each package and place in the freezer.
Freezing in Ice
Herbs such as mint or borage may be frozen in ice cubes as a decorative addition to drinks. Place a single leaf or flower into each section of an ice cube tray, and then top up with water and freeze.
Alternatively, chopped herbs such as parsley, chives and basil can be frozen with a small quantity of water. Add equal amounts of water to chopped herb and freeze; the frozen cubes may be transferred to labelled plastic bags and later used to flavour soups and sauces.
Herb Oils and Vinegars
Herbs may also be added to oil or vinegar to preserve their flavours and create a useful cooking ingredient. To make flavoured oils, simply pour a flavourless oil, such as sunflower, into a jar filled with herbs such as tarragon, thyme or oregano and leave in a warm, sunny spot for a fortnight. Shake the jar every day, and then after two weeks, strain the oil into a clean bottle. You may also want to add a single sprig of herb into the new bottle for identification.
Herb vinegars can also be made the same way, although the herbs should be lightly crushed before steeping. Warm wine or cider vinegar, and then pour it over the herbs, before proceeding in the same way as preserving with oils.
Basil leaves may be preserved in jars of oil; the leaves may be removed to use in pasta sauces, whilst the remaining oil can be used in salad dressings.