Garlic Turned Green or Blue in Achaar (Lehsun): Is It Safe?
Garlic that turns green or blue in achaar, vinegar or lemon is safe to eat. The colour is a natural pigment made when garlic’s own sulphur compounds meet acid, and it says nothing about spoilage. What does mean “throw the jar out” is mould, a bulging lid, fizzing, slime or a rotten smell, and garlic kept in oil at room temperature, which carries a real botulism risk.
Before you start
- Green or blue garlic: safe, harmless pigment.
- Most likely when: garlic is crushed or cut, meets vinegar or lemon, and has been stored cold or is very fresh.
- Stop it: blanch cloves for 1 minute, or use well-dried, room-stored garlic.
- Throw out: fuzzy mould, bulging or hissing lid, slimy cloves, off smell.
- Garlic in oil: fridge only, use within 4 days, or freeze.
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Why garlic turns green or blue in achaar
A jar of lehsun ka achaar, a bowl of garlic in sirka, or ginger garlic paste with a squeeze of lemon. Two days later, the cloves have gone a startling turquoise. Many people throw it straight out. There’s no need.
Garlic carries sulphur compounds and an enzyme, alliinase (the garlic enzyme), kept apart inside its cells. Cutting, crushing or soaking in acid breaks the cells, the enzyme gets to work, and some of the sulphur products then react with the garlic’s natural amino acids, building small pigment molecules that happen to look blue, and when those blend with the garlic’s yellow ones the eye reads green. It’s chemistry with ingredients the garlic already had. Nothing was added.
Chinese cooks make this happen on purpose. Laba garlic, peeled cloves soaked in rice vinegar for weeks in winter, turns a deep jade green and is a New Year treat. Same reaction, same garlic, eaten happily for centuries.
Garlic that has been stored cold turns green more often, because cold storage builds up the very compounds that make the pigment.
Why some jars go green and others don’t
Three things tip the odds.
- Cold-stored garlic. Garlic kept in cold storage, or in your fridge, for weeks builds up more of one sulphur compound that leads to the pigment. Imported garlic that has been in cold stores tends to do it more; see desi vs Chinese garlic for how to tell them apart.
- Acid. Vinegar, lemon, imli or amchur speed things up. That is why achaar and sirka garlic go green while plain peeled cloves in a dry box rarely do.
- Freshness and bruising. Very fresh, moist garlic and bruised or crushed cloves change colour more readily than whole, well-dried bulbs dried in the sun for a few weeks.
A pinch of trace copper, from tap water or an old brass pot, can deepen the colour a little. That’s one more reason acidic achaar never belongs in unlined copper or brass.
How to keep garlic white in pickles and paste
- Choose room-stored, dry bulbs. Buy firm garlic with papery, dry skins, and keep it in a basket in a cool, airy spot, not the fridge, for the week before pickling.
- Blanch the cloves. Drop peeled cloves into boiling water for 60 seconds, then straight into cold water. Heat switches off the enzyme. The cloves stay whiter and the taste turns slightly milder.
- Keep it clean and dry. Dry the blanched cloves fully on a clean cloth for 1 to 2 hours before they go into oil or masala. Water in achaar invites mould.
- Use enough acid and salt. Follow a trusted recipe for garlic achaar. A typical vinegar pickle keeps the cloves fully covered in vinegar, never just coated in oil.
- Use glass or steel. Sterilised glass jars or food-grade steel, never unlined copper, brass or aluminium, for anything sour.
For ginger garlic paste, adding a spoon of oil and a little salt, and keeping it in the fridge, is the standard method. Our guide on storing ginger garlic paste safely gives the times and the freezer method.
Green garlic vs spoiled achaar: keep or throw
| You see | What it means | Do |
|---|---|---|
| Green, blue or turquoise cloves | Harmless pigment | Keep and eat |
| Pinkish or reddish tinge | Also a harmless pigment | Keep and eat |
| White fuzzy or coloured mould | Mould growth | Throw whole jar |
| Bulging or hissing lid, bubbles | Gas from microbes | Throw, don’t taste |
| Slimy cloves, cloudy liquid, bad smell | Spoilage | Throw whole jar |
A thin white film on top of vinegar achaar is sometimes a harmless yeast, but if you can’t tell film from mould, don’t gamble. The full guide to pickle jars, salt and when to discard is in homemade achar safety.
Myth: green garlic in achaar is poisonous
People assume an odd colour means poison. For garlic in acid it doesn’t. The real danger is invisible, and it has nothing to do with colour.
Garlic grows in soil, and soil can carry spores of the germ that causes botulism. Those spores wake up in exactly the conditions a jar of garlic in plain oil provides: no air, low acid, and a warm kitchen shelf. The toxin can form with no smell, no bubbles and no colour change. So a lovely white clove in oil on the counter is far riskier than a turquoise one in vinegar in the fridge.
Homemade garlic in oil, including garlic-infused oil and garlic confit, must go in the fridge straight away and be used within 4 days, or frozen. Never keep it at room temperature, and never “top up” an old jar. Botulism signs, usually 12 to 36 hours after eating, are double or blurred vision, drooping eyelids, slurred speech, trouble swallowing and weakness spreading down the body; this is an emergency, so go to hospital at once. Never taste food from a bulging, leaking or hissing jar. Honey is never given to babies under 1 year, including in garlic honey.
Green garlic questions
Is green garlic in achaar safe to eat?
Yes. The green or blue colour is a harmless pigment made when garlic’s own sulphur compounds meet acid. Check the jar for mould, bulging and bad smells instead.
Why did garlic turn blue in vinegar?
Acid helps garlic’s enzyme and sulphur compounds react with its natural amino acids, forming blue pigments. It happens more with cold-stored or very fresh garlic.
Why does ginger garlic paste turn green?
Crushing garlic and mixing it with anything acidic, including lemon or some ginger, triggers the same harmless pigment. Blanching the garlic first reduces it.
How do you stop garlic turning green in pickles?
Use dry, room-stored bulbs and blanch peeled cloves in boiling water for 60 seconds before pickling. Dry them fully before they go into the jar.
Does green garlic taste different?
Barely. Most people notice no difference in taste. Blanched garlic is slightly milder than raw.
Can you store garlic in oil at room temperature?
No. Garlic in oil at room temperature can grow botulism toxin without any sign. Keep it in the fridge and use within 4 days, or freeze it.
How do you know if garlic achaar has gone bad?
Mould, a bulging or hissing lid, bubbles, slimy cloves, cloudy liquid or a rotten smell. Throw the whole jar out and never taste it to check.
Why did garlic turn pink?
Pink or reddish garlic is a related harmless pigment, common in cut or pickled garlic. It is safe to eat.
What is Laba garlic?
A Chinese winter pickle of peeled garlic soaked in rice vinegar until it turns jade green. It shows that green garlic is a normal, edible result of acid.
Is it safe to keep garlic achaar in a brass or copper pot?
No. Acidic food should never be stored in unlined copper or brass, because the acid pulls metal into the food. Use glass or steel.
For other puzzling colour changes in the kitchen, explained without scare stories, visit Kitchen Science, Honestly.