There are two primary reasons that a recipe instructs you to salt (then pat dry, then rinse) your sliced or cubed eggplant. (And when this happens, you groan! You drag out the colander! You sometimes don't oblige at all.)
BUT in On Food and Cooking, Harold McGee surmises that the added salt changes our perception rather than the eggplant's actual flavor. AND in How to Pick a Peach, Russ Parsons writes that salting does not remove bitterness—and he recently did the test to prove it.
BUT, as Parsons explains, the shriveled cells are actually better able to absorb oil during frying, which means a creamier, silkier texture as opposed to a meatier, chewier one. And in The Food Lab, Kenji López-Alt focuses on air, not oil: The key for optimally-textured eggplant is removing air—breaking down the cell structure and pressing out the air in between—and this can be achieved by microwaving eggplant slices between a sandwich of paper towels and plates before you fry.
Okay, so bitterness and oil absorption, but with much dispute. In The New Vegetarian Cooking for Everyone, Deborah Madison recommends salting slices or cubes for 30 minutes to remove bitterness, 60 or more to achieve better fried eggplant.
So what should you do? Well, before you add an hour or two to your dinner prep, ask yourself these questions (to see if you can avoid it):
If you're an eggplant super-taster (congratulations?), you may want to salt your eggplant for reassurance no matter what you're making with it. As Madison confesses, "I know some cooks who always salt their eggplants and others who never do, reflecting perhaps their own sensitivity—or lack thereof—to eggplant."
If you've been getting good-tasting results without salting, continue as you were.
Unless, that is, you find yourself with an old, squishy eggplant or you're frying it and looking for that yielding, silken texture. (Read on.)
"Eggplant that’s freshly picked, harvested before it’s overly mature, and eaten within a few days is naturally sweet and doesn’t need salting, nor do the slender Asian varieties," writes Deborah Madison in The New Vegetarian Cooking for Everyone.
You want young eggplants, and Mark Bittman assures readers of How to Cook Everything Vegetarian that if "the eggplant is fresh and firm, chances are it will taste pretty good without salting it, regardless of the variety." Parsons goes so far as to say your eggplants should be "rock-hard."
If fresh eggplant is not an option (or if age is impossible to determine), look for the small Asian varieties (though not the seedy green Southeast Asian ones prized for their bitterness—that'd be ironic). And for those that have been in storage or, in Madison's words, are "over the hill," salting removes some of the bitterness that heightens with age. Large, soft, or especially seedy eggplants? Take the time and energy to salt.
Are you roasting, charring, grilling, or microwaving a firm, young eggplant? Pass "Go" and collect your unsalted eggplant.
If you're going to fry your eggplant—pan-fry, deep-fry, sauté in a generous slick of oil—and you want a silky texture (for pasta alla norma or eggplant Parmesan, for example—something that melts rather than fights back), you'll want to take the time to salt.
The exception? If you're frying eggplant and you don't mind if it's chewier and truer to its shape—maybe that's how you like your caponata or ratatouille—skip the salting.
To make things a bit more confusing, Ottolenghi, who is arguably our generation's Greatest Eggplant Advocate, salts his eggplant sometimes, but not others. (Oh boy.) In Plenty More, eggplant cubes are not salted before they are deep-fried and added to udon noodles; but eggplant chunks are salted in his Eggplant, Potato, Tomato, where they're fried in 1 centimeter of oil. Hmmm. The variation in method may be the result of different intentions for the eggplant's texture or of the unique properties of deep-frying versus pan-frying. In his Eggplant Pahi, the eggplant slices are fried, salted, and then left to drain.
Seems like another rabbithole entirely—and we need answers!
Salt your eggplant if it's old and soft and/or if you're frying it and looking for a texture so accommodating it will bend over backwards for you—or, if you're doing absolutely everything in your will to make sure it doesn't taste bitter.
And to prove the point, a brief breakdown of eggplant recipes based on which side of the salt-no salt coin they fall:
Above, the slices are salted and pressed, but not for any extended period of time.
The eggplant is seasoned before being baked, but it is not salted for an extended period of time.
Above, the eggplant gets soaked in cold water while the other ingredients are prepared in order "to remove the bitterness."
What's your go-to, no-questions-asked eggplant cooking method? Tell us: We want to know.