Why Garlic Turns Green or Blue? Is It Safe or Risky to eat?

I had the same questions as you – Why does Garlic turn green or slightly blue? Is it safe to eat green garlic?

Garlic, like all vegetables and organic foods, contains natural substances called enzymes (alliinase). Sometimes sulfur compound called alliin present in the garlic react with it and turns the garlic green or slightly blue.

Garlic rarely changes color when it is still fresh. Because enzymes (alliinase) and sulfur compounds called alliin are still intact when fresh.

As soon as you cut, chop, or mince the garlic, the two compound interacts and create an Organosulphate compound called allicin. This allicin is responsible for the pungent smell and taste of garlic.

This Allicin compound when it comes in contact with acids (from Vinegar or Lemon) or certain minerals reacts to form greenish or slightly blue color.

Mature or old garlic usually means that natural enzymes and chemicals are broken down making it more likely to react with sulfur and turn green. 

Side Effects and Benefits of Eating Raw Garlic Daily

Desirable conditions that help Garlic turn Green

Here are some desired environmental conditions that make garlic turn green: 

– pH

pH describes how acidic or alkaline an aqueous solution is.

It has usually been found that the presence of acidic substances like lemon or vinegar may cause a color change.

– Garlic Age

Aged garlic is more prone to turning to green color. This is because, in old garlic, the enzyme breakdown is faster leading to a faster reaction to sulfur that eventually leads garlic to turn green.

– Warmer Temperature

Garlic that has been blanched or semi-cooked at simmering low temperatures is more likely to turn color. This is because the enzymes and chemicals are being exposed during this process. Hence, they can react and change color.

– Garlic Form

Grated garlic and minced garlic are more likely to turn color. Because they are cut or opened, the enzymes are left exposed.

In addition, the enzymes are more likely to break down in these forms as they are more exposed to air. 

16 Amazing Facts About Garlic that you may not know!

What Should Garlic Actually Look Like?

Fresh garlic has white to yellow-colored flesh once the papery skin is removed. Green or blue garlic is not its natural color.  

If Garlic is Cured and Stored properly it would not lose its natural color.

Fresh Garlic

Is it safe to eat Green or Blue Garlic?

Yes, Green garlic is absolutely safe to use!

Though the color may surprise you and some may find it to be horrible. However, it will not kill you or make you ill!

Only chemical reactions are to blame!

We will admit such colors can be off-putting. Though colored garlic is not bad, it does mean you should use it up fast as you may soon need to discard it. 

But if the color change is just too much, you might consider throwing it out. Better be Safe than Sorry!

Laba chinese garlic is a popular traditional chinese dish that has green or blue color. It is made with vinegar and the acid from it causes the garlic to turn green or blue.

laba blue garlic

How to Keep Minced Garlic from Turning Green?

Worried about your garlic turning green? Here are ways that can help to ensure the garlic retains its natural color.

1. Keep it Refrigerated

Cold temperature can help to inhibit any chemical reactions. Because low temperatures can delay food degradation, the release of enzymes does not occur. In turn, reactions are less likely to occur. As a result, the color change is less likely to happen.

Read here to know How Long Does Garlic Last (In the fridge)?

2. Use Fresh Garlic – Do Not Delay

Going to use garlic for a special dish? Do not delay! Avoid keeping your garlic peeled and left uncovered. In addition to decreasing quality, the chances of color change increase. 

3. Avoid Using Garlic With Acid

In case you are attempting a recipe that has an acidic ingredient, try to ensure garlic and acid do not come in contact. Try to reshuffle the steps to make sure the garlic is already cooked down before adding the acid. 

4. Cook Onion and Garlic Separately 

Cooking onion and garlic together can create a color change in the garlic. Try to cook your onions and garlic separately and then combine them. In turn, this will prevent the greening of garlic

How to Prevent Garlic From Turning Blue When Pickled?

The acid used during pickling reacts with the allicin and causes the garlic to turn green. This would depend on factors like the age and form of garlic.

Here are the steps that you can take to keep the garlic green as much as possible.

  • Using distilled water may help as it is free from minerals that can react with allicin.
  • Avoid using a copper or aluminum pan. Instead, use stainless steel ones.
  • Iodine present in the salt may also cause this so use iodine-free salt.


While you may get worried about the green or slightly blue color of garlic, it is not something that you should get worried about.

Garlic can turn green or blue when the sulfur in it reacts with the enzymes present. Garlic in its full original form is less likely to turn green but mincing or chopping can promote this.

Further, acid, iodine, or minerals from the metal container like copper or aluminum can also promote the green color.


  1. https://pubmed.ncbi.nlm.nih.gov/16448192/