Why Your Garlic Might Be Blue, Green, or Even Purple

Colorful garlic might catch you by surprise, especially if you’re used to standard white garlic. Here’s what to know.

Garlic is a beloved ingredient for obvious reasons—it’s equal parts good and good for you. In fact, if a recipe says two cloves, we say double it. And while you’ve likely got a few bulbs laying around the kitchen (they *do* have a six-month shelf life if stored properly), discovering your garlic has turned blue, green, or purple might cause a bit of a jump scare when you’re peeling those cloves.

Here’s the good news: This isn’t a reason to panic. Blue, green, or purple garlic is perfectly safe to eat—unlike fuzzy garlic. These colors have different causes, though, and your garlic might turn blue or green during cooking, while purple garlic is an entirely different situation. Let’s break down this wild phenomenon.

Why is my garlic blue or green?

The reason your garlic turns blue or green is actually related to the same scientific reaction that causes its fragrant smell.

“The chemical precursors of these compounds start out safely locked away within individual cells in the plant,” The Food Lab author Kenji Lopez-Alt writes in Serious Eats. “As you cut or grate them, they get exposed to each other, where they end up reacting, with the aid of enzymes.”

Let’s break this down a little further: It all has to do with those chemical precursors and their reaction with each other and other amino acids that make clusters of carbon-nitrogen rings called pyrroeles. They form green compounds (kind of like green chlorophyll) and change the color of your garlic when it’s heated up (or mixed with acid), which explains why your garlic might change colors when it’s being cooked.

Fresh purple garlic in basket made from newsprint papers
istetiana / Getty Images

Does this mean my garlic has gone bad?

No. While you might find it off-putting to cook with green or even blue-hued garlic, this isn’t a sign your garlic has gone bad. Older garlic, however, is more likely to change colors because it builds up more of those chemical precursors than a fresh bulb would.

Green-blue garlic also produces a stronger flavor and smell. For some, that might be the desired effect, while for others it might not. So how do you avoid changing hues if you want to stick to regular, old white garlic? Lopez-Alt suggests keeping your garlic cold while cutting or grating (remember, heat speeds up that chemical reaction!) and cooking it separately from onions—which can similarly speed up the reaction process and turn your garlic colors.

The TL;DR answer: You can eat blue or green garlic—and it might even add a little extra flavor to your dish.

Why is my garlic purple?

Purple garlic is different from blue-green garlic (and its originating white garlic). In fact, it’s actually a different variety altogether, and that color variation is not just the result of a chemical reaction, Allrecipes reports. Purple garlic is “juicier” than its counterparts and boast a more mild flavor. It’s also (typically, at least) harder to get your hands on and available more so at specialty stores. 

Do I need to store purple garlic differently?

While purple garlic serves the same purpose as white garlic and they can be used interchangeably, they are stored differently. According to Allrecipes, purple garlic has a shorter shelf life and loses flavor as it dries out. As such, you should try storing purple garlic in a mesh bag at room temperature during higher humidity times and in a small clay flower pot in a cabinet during the winter.

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