What Is Black Garlic? Ask Paul

The thing that surprises anyone eating black garlic for the first time—after the color—is that it doesn’t taste particularly garlicky. The flavor is sweet, tangy, rich, and concentrated, like molasses or dried dates, with an earthy savor; the texture is sticky and spreadable.

You can find “black garlic seeds” on Amazon, but those are a scam; black garlic is not a separate variety of garlic. It’s made by putting ordinary heads of garlic through a warm aging process that is often called fermentation but—as with black tea—is not technically fermentation.

Fermentation involves microorganisms, bacteria, yeasts, and molds transforming a foodstuff; making black garlic doesn’t require external microbes. Instead, it’s tantamount to very slow cooking.

The browning reactions of Maillardization and caramelization that happen during cooking, producing the wonderfully complex cooked flavor of roasted coffee, grilled meat, and dulce de leche, typically take place in minutes or hours, at a temperature above 250°F. The genius of black garlic is that the same reactions can happen at a lower temperature, just 140°F, if the temperature is maintained for months on end. 

The super-slow cooking allows the garlic to transform more thoroughly, without the usual risk of burning or drying out. Time gives many more of the garlic’s sugars and amino acids an opportunity to undergo the Maillard reactions, producing a multitude of complex and unexpected flavors.

Since the garlic head is intact during the process, the usual formation of pungent garlic flavor, which occurs through enzymatic activity when garlic is cut, never happens. The enzymes that are responsible for those flavors being formed in cut garlic are destroyed by the heat; that’s why black garlic doesn’t taste garlicky.

You can make black garlic at home if you have time and space: a slow cooker on the “keep warm” setting for 60 days will do the job. Or you can buy it.

Test cooks at Cook’s Illustrated tried substituting black garlic for fresh garlic in familiar garlicky applications such as pasta and pizza, and found it overly subtle. Instead, it works well if you don’t really think of it as garlic: Puree it into sauces, salad dressings, and stews to add roasty flavor. It works wonderfully in recipes that contain soy sauce, balsamic vinegar, dried chiles, or sesame; and its richness complements savory foods like beef or mushrooms.