Herb salt and herb oil: what keeps and what doesn't

By the end of summer there are always more greens than anyone can eat. I don't like drying dill and parsley — they lose almost all their flavor. There are better ways.

Dry herb salt

Mix 3 parts coarse salt with 1 part thoroughly dried herbs: rosemary, thyme, dill seed, dried garlic. Grind them together in a mortar so the herbs release their aroma into the salt. It keeps like ordinary salt, in a dry jar with a lid. Great on meat, potatoes and roasted vegetables.

Salted greens

Finely chop fresh greens — dill, parsley, celery leaves, green onions — mix with salt at roughly 200–250 g of salt per kilogram of greens, and pack tightly into clean jars. Keep them in the fridge, where they last for several months. This is now salt as much as greens: add it to soup at the end and go easy on any extra salt.

Herb oil: the safety rule

A bottle of oil with sprigs of fresh rosemary and garlic cloves looks lovely on a shelf, but that's not how to store it. There's no oxygen in oil, and plants straight from the garden can carry the spores of the bacteria that cause botulism. At room temperature that environment suits them, and spoiled oil doesn't change in taste or smell.

• Fresh herbs and garlic in oil belong in the fridge and should be used within 3–4 days.
• For longer storage, freeze chopped herbs with oil in ice cube trays. One cube in the pan, and you have the base for a sauce.
• Herb butter: roll it into a log in parchment, freeze it and slice off rounds as needed.

Oil with dried herbs is a much safer option, but the herbs must be completely dry and the bottle clean and dry.