Preserving Herbs and Spices

A few sprigs of green herbs laying on a naturally colored cloth

When drying herbs, leave room for air flow to prevent mold and mildew from growing.

In vegetable gardening, harvest time can feel like a tidal wave. Herbs, on the other hand, can be harvested as needed during their growing season. It's easy to enjoy their fresh flavor after their season is over, too. Here are three ways to preserve and enjoy your garden's flavors, year-round.

Dried Herbs and Spices

To dry herbs for later use, harvest them when the plants begin to flower. For spices, like coriander and sesame, harvest when the seed-bearing structures have had time to dry. Both should be dried rapidly in a well-ventilated, darkened room. If the leaves are dusty or gritty, wash them in cold water and thoroughly drain them before drying. As soon as the leaves or seeds are dry, pack them in plastic or glass containers that can be closed tightly.

You can also dry herbs in the oven and microwave. These methods do require caution however; cooking the herbs instead of drying them will ruin their flavor. Dry herbs in an oven set at 180 degrees or below, until they are dry and crumble easily. You can also microwave them, 30 seconds at a time, until they are crisp but not burned. Do not leave these appliances unattended while in use.

Thoroughly dried herbs and seeds will not spoil, but the flavor will fade over time. Leafy herbs, like parsley, basil, and oregano, remain fresh for 1-3 years. Ground spices, such as paprika and nutmeg, can be kept for 2-3 years. Whole spices, like peppercorns, may retain their flavor for up to 5 years.

Fresh-frozen Herbs

Small, colorful piles of turmeric, cumin, and dried rosemary

Whole spices have a longer shelf life than ground spices. Both last longer when stored in cool, dry, and dark spaces.

Drying is the traditional way to preserve herbs, but freezing is just as simple. Harvest the herbs from your garden, wash them well, and then pat them dry. Place them in a single layer on a baking sheet in the freezer. This ensures that they won't freeze together in one big clump. Transfer the frozen herbs to an air-tight bag, labeled with the date.

Woody-stemmed herbs like dill, sage, rosemary, and thyme freeze best when left on their stalks. When you're ready to cook you can add whole stalks and then retrieve them before serving. You can also chop or snip the leaves of frozen herbs directly into your dish, just as you would with fresh herbs.

When you use frozen herbs, be aware that they will be limp when thawed. This makes them less attractive and better suited to cooked recipes.

Herbal Vinegars

Herbal vinegars are a third option for anyone hoping to harness and extend the flavors of the garden. Salad dressings, marinades and basting liquids can all benefit from a splash of herbal flavor. Vinegars can also add flavor to many dishes, like scrambled eggs and stir-fries. For full flavor, make sure to use the right part of the herb. A good herbal vinegar recipe will tell you which parts of the plant to use.

A close and tight view of different green leafy herb plants.

Avoid crushing leafy herbs; this will help preserve the flavor.

Creating an herbal vinegar is like canning; proper sanitation is necessary, regardless of which recipe you're following. The guidelines below, along with these resources and recipes from National Center for Home Food Preservation and CSU Extension, can help you prepare herbal vinegars safely and effectively:

  • Wash AND sterilize all container components beforehand, including jars, corks, lids, and caps. Boiling water is effective in sterilizing your materials:
    • Boil glass for 10 minutes
    • Scald screw caps in water just below the boiling point or follow manufacturer's directions
    • Dip corks in boiling water 3-4 times
  • Heat vinegar to just below boiling (190F) immediately before pouring it into a container.
  • Wash herbs gently and then sanitize with a dip in a solution of 1 teaspoon of household chlorine beach per 6 cups of water. Rinse after dipping and allow to dry.
  • Fill the sterilized containers with herbs and vinegar while they are still warm.
  • Do not over-fill the containers:
    • Leave ¾ of an inch of space unfilled at the top of each jar
    • 3-4 sprigs of fresh herbs per pint of vinegar OR
    • 3 TBSP of dried herbs per pint of vinegar
  • Let the containers sit, unmoved, until they are cool.
  • Store containers in a cool-dark place for 3-4 weeks while the flavors are extracted.
  • Use herbal vinegars within 3 months. Refrigeration may extend the life of the vinegar to 6-8 months.
  • Never consume a vinegar that shows any sign of spoiling: cloudiness, bubbles, or slime.

Also on Gardening Solutions

UF/IFAS Publications