Preserves & pantry

How to Cure and Store Olives at Home

The pyramids of green, violet and wrinkled black olives in the Marrakech olive souk are one of the great sights of the medina — and every one started as a fruit too bitter to eat raw. Curing is the process that strips that bitterness and turns raw olives into a staple that sits on every Moroccan table and inside half its tagines. Done at home it takes patience, but the method is simple and the keeping is easy.

Difficulty: Moderate
Active time: 20 min, then days-to-weeks curing
Yields: A jar of cured olives
Best tool: A large jar or crock

What you need

Fresh raw olives — green (firm) or black (ripe)
Plenty of coarse salt for brine or dry-curing
Water for the daily change (green olives)
Storage jars, olive oil, and aromatics: preserved lemon, garlic, chilli, herbs, lemon slices
A weight to keep olives submerged

Why it matters

Raw olives contain oleuropein, a compound so bitter it makes the fruit inedible straight from the tree. Every curing method — water, brine, dry salt or lye — is really just a way to leach or break down that bitterness. Understanding which method suits which olive is the whole craft: firm green olives take well to a long water or brine cure, while soft, ripe black olives are classically dry-salt-cured into the wrinkled, intense olives Morocco is famous for.

Storage is the second half. Once cured, olives are kept in brine, often under a seal of olive oil, and this is where Moroccan cooks make them their own — layering in preserved lemon, garlic, chilli, cracked coriander and herbs so the olives take on the flavours around them. Those seasoned oil-slicked olives are as much a signature of the country as the tagine they garnish.

Step-by-step method

1

Sort and prepare the olives

Discard any bruised or damaged fruit. For green olives, crack or slit each one (a light tap with a mallet, or a knife slit) so the cure can penetrate — cracked green olives are a Moroccan classic. Ripe black olives for dry-curing are usually left whole.
2

Water-cure green olives

Submerge cracked green olives in fresh water, weighted so they stay under. Change the water every day. Over one to two weeks the bitterness leaches out into the water; taste one after a week to judge how far it has to go.
3

Or dry-salt-cure black olives

For ripe black olives, layer them with plenty of coarse salt in a perforated container over a tray. The salt draws out moisture and bitterness, which drips away. Toss every few days; over two to four weeks they shrivel and mellow into intense, wrinkled olives.
4

Move to a holding brine

Once the bitterness is gone, transfer green (or brine-style) olives to a fresh brine — a salt solution strong enough to float a raw egg is the traditional test. Dry-cured black olives can simply be tossed with a little oil.
5

Season the storage jar

Pack the cured olives into clean jars with your aromatics: strips of preserved lemon, sliced garlic, dried chilli, cracked coriander seed, bay, and a few lemon slices are all classic. Add brine to cover for green olives.
6

Seal under oil

Top the jar with a layer of olive oil to seal the surface from air, then close it. The oil protects the olives and slowly carries the aromatics' flavour into them.
7

Rest, then keep cool

Let the jar sit for a few days to a week so the flavours mingle before eating. Store cured, sealed olives somewhere cool; once opened, keep them in the fridge and always submerged.

Common mistakes

Eating them before they are cured. Raw or under-cured olives are punishingly bitter. Taste as you go and do not rush the leaching.
Not changing the water. Water-curing works by removing bitterness into the water — leave it unchanged and it saturates and stalls, and can spoil. Change it daily.
Olives above the brine. Any fruit exposed to air can mould. Keep them weighted under the brine, and sealed under oil for storage.
Too weak a brine. A weak storage brine will not preserve. Use a proper salt concentration — strong enough to float an egg is the old benchmark.
Using the wrong cure for the olive. Trying to dry-salt firm green olives, or water-cure soft ripe ones, gives poor results. Match method to fruit — water/brine for green, dry salt for ripe black.
Dirty jars. As with all preserving, contamination is the main failure. Start with sterilised, clean jars and utensils.

Tips

Cracked green olives with preserved lemon, garlic and chilli are a quintessential Marrakech table olive — season boldly.
Save some of the flavoured oil from the jar; it is delicious for dressing salads or dipping bread.
If you cannot cure your own, you can buy cured olives and simply re-season them in oil with preserved lemon and herbs for a homemade Moroccan touch.

Recipes and dishes that use this

Frequently asked questions

How do you take the bitterness out of olives?

By curing them. Green olives are usually cracked and soaked in water changed daily (or held in brine) for one to two weeks; ripe black olives are dry-salt-cured for a few weeks. Both methods leach out the bitter oleuropein until the olives are edible.

How long does it take to cure olives?

It depends on the method: water-curing cracked green olives takes one to two weeks, while dry-salt-curing ripe black olives takes about two to four weeks. Always taste to judge when the bitterness has gone.

How do you store cured olives?

Keep cured green olives submerged in a strong brine, and seal the jar surface with a layer of olive oil to block air. Store somewhere cool, refrigerate once opened, and always keep the olives under liquid.