Why Is My Garlic Blue?

With a few notable exceptions, such as blueberries, blue raspberry candies, and some smoothies, blue is not the color you want your food to be, especially if you didn’t plan on it. Blue (or turquoise or green) garlic is particularly striking. Garlic should be beige, golden brown, or a deep, sticky black , but like the bright patterns on a poison frog, blue garlic raises some red flags.



Now playing

5 of our favorite movies and documentaries about dinosaurs
Friday 11:15


Now playing

How long does liquor really keep after you open the bottle?
Thursday 12:02

Why is this happening?

I first encountered bluish garlic during a sous-vide experiment, although it is most often seen during pickling. The blue hue is due to a chemical reaction between a sulfur-containing amino acid (alliin) and an enzyme (alliinase). These two compounds are isolated from each other in whole garlic, but chopping, chopping, and chopping garlic exposes these two compounds to each other, giving garlic its famous pungent flavor and aroma. According to The Spruce Eats , the addition of an acid (such as pickling vinegar) can cause a discoloration, although metals can also cause a similar reaction:

When garlic is combined with an acid (such as vinegar), allicin reacts with the amino acids in the garlic to form carbon-nitrogen rings called pyrroles. Pyrroles bonded together form polypyrroles, which cast off colors. Four pyrroles grouped together give a green color (which is why chlorophyll is green). Three pyrroles joined together form blue.

A similar color reaction can occur when garlic comes in contact with certain metal minerals, including copper, aluminium, iron, and tin. Minerals can come from pots or pans made from these metals, or from micronutrients in the water.

The acid itself is not consumed in the reaction, but it does help facilitate the change by further breaking down the cell walls. It is possible that you have marinated 50 cloves of garlic without seeing this color change, depending on the freshness of the garlic you have marinated. According to food writer Harold McGee , aging garlic to promote color change is a common practice in northern China, where onions are soaked in vinegar to make Laba garlic, a pickle prized for its bright color and sour, slightly spicy taste. :

According to chemists at the China Agricultural University in Beijing, aging garlic gives it the opportunity to accumulate large amounts of one of the coloring chemicals; Fresh garlic almost never turns green. And the strong green color of Laba garlic only develops with acetic acid, the main acid in vinegar (also found in sourdough), because it is especially effective at disrupting internal membranes and mixing cellular chemicals that react together to create a green pigment. The pigment itself turns out to be a close chemical relative of chlorophyll, which gives color to all green leaves.

Can I eat this?

As you might guess, blue, turquoise, and green garlic are perfectly safe to eat and don’t taste much different than beige garlic. You can even make your own Laba garlic and eat it as a brine along with dumplings (or any other fatty food that would benefit from a sour, spicy brine).

How to Prevent Blue Garlic

While blue garlic does not cause bodily harm, the blue color can look a little off-putting in some cases, especially when chopped into small pieces and spread on garlic bread or stuffed into chicken breasts.

Using fresh garlic or cooking it before it is exposed to the acid can help. In the case of pickling, rapid blanching can deactivate some of the enzymes responsible for the color change. Avoiding copper, aluminum, and cast iron cookware can also reduce the chances of your garlic turning blue on its own, but the easiest way to deal with blue garlic is to eat it. At the very least, it will give you a chance to look really chic at a dinner party, which is always my goal when I dine with a group of friends and colleagues.


Leave a Reply

Your email address will not be published. Required fields are marked *