The Best Way to Cook Broccoli Rabe, According to Science

But many people don’t share this fondness. In fact, bitterness might be the most underappreciated of the five tastes. 

But I’d argue that the pungency and assertiveness of raw kale, for example, is perfect in the right context: It can add complexity, cleanse the palate, and/or offer refreshing balance to rich, savory, or sweet foods.

This is also the case for broccoli rabe. Most recipes that use it jump through hoops to tame the green, blanching and shocking it to quell the compound responsible for the bitterness before cooking it. 

But a dunk in hot water eliminates the vegetable’s bitterness almost entirely, stripping it of its unique character. 

If you ask me, broccoli rabe is at its best when its pungency is tempered, not erased. And that’s exactly what Senior Editor Steve Dunn set out to accomplish when he was developing a simple broccoli rabe side dish. 

Steve dove deep into the science of the green to get to the root of its bitterness, and discovered that he could dial in the rabe’s pungency by both cutting and cooking it strategically.

Broccoli rabe is a boldly pungent leafy green. Though it shares a name with conventional broccoli, rabe is actually closely related to the spicy turnip. In fact, in Puglia, where the green is beloved, it’s called cime di rapa, or “turnip tops.”

All parts of the vegetable—from its generous leaves to its florets to its stems—are edible.

Rapini and broccoli rabe are the same bitter, mustardy green by different names. You may also see the vegetable labeled as “broccoli raab.”

When broccoli rabe is cut or chewed and its cells are damaged, two components stored mainly in its florets—the enzyme myrosinase and a bitter-tasting substrate of the enzyme called glucosinolate—combine. 

When that happens, some of the glucosinolates are converted into even harsher-tasting isothiocyanates. 

In other words, the pungency we taste in broccoli rabe is the vegetable’s defense mechanism when under attack.

Knowing that more cutting = the creation of more bitter isothiocyanates, it pays to be strategic about how you break down your broccoli rabe.

When Steve was developing his recipe, he performed a quick side-by-side test. First, he fully chopped one sample of broccoli rabe, florets and all. Then, he cut a second sample into larger, bite-size pieces, leaving the leaves intact. He sautéed both batches and took a taste.

Sure enough, the more intact pieces were considerably more mellow.

The bottom line? If you want your broccoli rabe to taste less bitter, be careful with how much you chop it. Leave the leaves intact, if you can, as the leaves are where most of the bitter-causing enzyme resides. And chop the stems into large bite-size pieces.

Cooking also helps temper broccoli rabe’s assertiveness.

When broccoli rabe is cooked, the high heat deactivates the myrosinase enzyme in the vegetable, stopping the reaction that contributes most of the bitter flavor in the first place.

You could simply sauté the leaves and chopped stems to achieve this—but Steve advocates for broiling in his recipe. 

In addition to being almost entirely hands-off, broiling comes with an additional perk: It encourages deep browning and rich caramelization through the Maillard reaction. Those flavors help further balance the broccoli rabe’s bitterness.

Try it yourself using Steve’s recipe below.