Basil: An Herb Society of America Guide
Preserving in Oil & Salt
Basil can also be preserved by placing leaves in a jar over 1/2 inch of olive oil, layering the leaves with oil and a sprinkling of salt, and storing in the refrigerator (38, 62). Individual basil leaves can be removed and used as needed. One problem with this method is the potential for botulism to develop, even in the refrigerator. For safety, do not keep oil longer than 2 weeks, or use another preservation method (23).
Leaves can also be preserved by layering in salt alone (9, 38). Susan Belsinger recommends layering sea salt and basil leaves in a glass pint jar with a plastic lid and storing in the refrigerator. Leaves will stay fresh and last until the next harvest season. Salt can then be used in soups and sauces or sprinkled over vegetables (8).
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