Keeping herbs for winter use
Herbs have the best flavour when they are freshly cut, however there are ways to be able to use herbs through the winter when they are out of season.
Keep using fresh herbs
Frozen herbs
Herb vinegar
Herb oil
Keep using fresh herbs
The best way to have herbs through the winter is to keep growing them. In many areas, many hardy herbs can be kept growing by giving them the protection of a greenhouse or placing them under a cloche. Sage, thyme, rosemary and bay can all be protected from the worst of the winter weather, giving soft and fresh new leaves throughout the year.
Perennial herbs, such as mint and marjoram, should be cut back in August, so that new shoots will provide a supply of fresh, new leaves later in the year. Hardy annuals, including chervil and parsley, should be sown in July to give a winter crop.
Tender herbs, such as basil and coriander, can remain outside as long as the weather permits. If they are grown in containers, they should be brought indoors when it gets too cold, and kept on a sunny window sill.
Frozen herbs
Herbs with soft leaves, (such as basil, coriander, chives, mint, parsley and tarragon), retain their colour and flavour best once picked if they are frozen rather than dried. Pack washed whole sprigs into labelled plastic bags and freeze (they will crumble easily once frozen).
If planning to store the herbs for any length of time, it is best to blanch them first. Dip them in boiling water, then in iced water, and pat them dry before freezing.
You can also freeze herbs in ice-cube trays. Chop the herbs coarsely and add one tablespoon of water to each tablespoon of herbs in an ice cube tray.
Herb vinegar
An alternative is to preserve hardy herbs by soaking them in vinegar (either wine or cider). Crush the herbs lightly to release their flavour, and loosely fill a clear, screw-topped container with the herb and then cover the herbs with warmed vinegar. Use about 250 ml (9 fl oz) of vinegar for every two tablespoons of the herb.
Do not use metal or metal-topped container as vinegar is corrosive.
Leave to stand for a couple of weeks then strain the vinegar through coffee filter paper to separate the vinegar from the herb leaves, discard the leaves.
Store the recovered vinegar in airtight bottles and store out of sunlight. Don't forget to label the bottles so that you know what herb has been used to flavour the vinegar.
Herb oil
The flavour of aromatic herbs, such as basil, bay, dill, French tarragon and thyme, can be captured by soaking them in oil.
Loosely fill a clear, screw-topped container with crushed herb and cover in a mild olive oil, use about 250ml (9fl oz) of oil for every two tablespoons of the herb. Leave on a sunny window sill for about two weeks, shaking the container every day.
To make the flavour more intense, repeat the process by straining off the leaves and reusing the oil with some fresh leaves; again, leave to soak for a further two weeks on a sunny window sill, shaking the container every day.
Finally strain the oil through coffee filter paper to separate the oil from the herb leaves, discard the leaves.
Store the recovered oil in airtight bottles and store out of sunlight. Don't forget to label the bottles so that you know what herb has been used to flavour the vinegar.