The Food Lab: All-American Eggplant Parmesan
If you had asked the 14-year-old me what my three least favorite things in the world were, I would have answered "my sister*, She-Ra, and eggplant."
*I won't say which one, but you know who, Aya.
But I would have rather sat through a She-Ra marathon with my sister than be forced to down a bite of the slimy, bitter stuff. Later on down the line, I realized that it's not really eggplant itself that's horrible, it was more just that my mom didn't really know how to cook it (sorry, Mom), and she's not the only one.
Most of the ingredients in Eggplant Parmesan are tough to mess up. And I'm not talking the traditional Sicilian style where un-breaded slices of eggplant are deep-fried in olive oil and delicately layered with tomatoes and mozzarella—I'm talking the all-American version. The kind where meaty slabs of eggplant get breaded and fried before being layered in a casserole dish with a cooked tomato sauce loaded with mozzarella and parmesan cheese.
The best bites of the dish are where the fried breading soaks up the sweet tomato sauce and swells in between the layers of meaty eggplant and gooey cheese. At its best, Eggplant Parm is like a tastier, more comforting, and (marginally) healthier version of Lasagna Bolognese (hey—my wife told me she wants to get more vegetables into our diet. This is my attempt).
Tomato sauce? No problem. Gooey Mozzarella? I can get that. Breading and deep frying? A bit messy, but nothing overwhelming. Properly cooking eggplant?Not so simple. Even if you manage to purge them properly of their bitter liquid (not an easy task!), they're still so airy and spongy that they instantly absorb any and all oil. Cook them too much, and they turn to mush. Don't cook them enough, and they are tough with a tannic, astringent bite.
I chatted with Ed about this a bit, and I think he put it best:
"The thing is, between eggplant parmesan and lasagna, you almost always want to pick the lasagna, because even at its worst, there's only so bad that meat, tomato sauce, cheese, and noodles can be. But bad eggplant is inedible."
And he's right: with eggplants, it's all or nothing. It's time to up those odds.
The Urge to Purge
You've probably heard that you can tell the "sex" of an eggplant by looking at the dimple on its bottom, and that male eggplants have fewer seeds than females. While it's certainly possible to tell the sex of certain things by examining their bottoms (like mandrills or crabs), eggplants are not one of them (in reality, eggplants don't even have a sex). This fact may explain the number of unemployed gender specialists I've been meeting lately.
So how do you find an eggplant with fewer seeds? The best way is to compare their weight—the less dense an eggplant is, the less seedy it will be. Of course, eggplants that are less dense are harder to work with—they turn mushy more easily, and absorb more oil while cooking—which makes this advice totally impractical.
Here's a better way to do it: just buy Italian eggplants. At least as far as eggplants are concerned, Italians are far less seedy than their larger American counterparts. They are also denser, less cumbersome to work with, and almost as widely available.
Even with dense Italian eggplants, you still need to purge them as the first step to any recipe (short of roasting them whole, that is). Why?
To demonstrate, I weighed out a 24-gram slice of eggplant before placing it in a bowl of oil. Twenty minutes later, I weighed it again.
As you can see, it's absorbed 92.3% of its weight in oil! If you've ever tried sautéeing raw eggplant, you know that they almost instantly absorb any oil in the pan, stick to the bottom, and burn. Like a sponge, their cells are held together into a very loose network with plenty of air in between. Before you can even think about cooking them, you need to figure out a way to remove that air.
To find the best way, I tried four different methods:
- Salting, resting, and pressing first gets rid of moisture through osmosis. Like a leaky water balloon, as the moisture leaves the eggplant, its structure weakens, allowing you to eventually press out the excess air. This works fairly well, but it requires quite a bit of pressure, it's easy to over or under-salt the slices, and sometimes you're still left with uncompressed sections in the center of each slice, which means undercooked, astringent finished results. It also takes upwards of an hour for eggplant slices to purge properly. No thanks.
- Steaming eggplant slices in a bamboo steamer will rapidly soften them to the point that you can easily compress them. It also makes them soggy and mushy. It's a technique better suited for eggplant that's going to be subsequently braised or mashed. Pass.
- Roasting eggplant slice uncovered is tough to do. Cook them dry, and they turn leathery and tough. Try and oil them before roasting, and the usual problem occurs: the oil gets instantly sucked in, and your eggplants still end up leathery and tough and greasy. Fail.
- Roasting eggplant slices covered by a layer of paper towels in between two sheet pans is by far the most successful in-the-oven way to do it. By lining a baking sheet with paper towels (or a clean kitchen towel), placing the slices on top, covering them with another layer of paper towel, then covering the whole thing with another baking sheet, the slices cook evenly and the paper towel absorbs excess moisture while at the same time keeping them just moist enough to keep from turning leathery. We've got a winner!
Roasting at 375°F for about 30 minutes was the way to go. Once the eggplant is fully cooked, you've still got to press to expel that air.
It's an pretty simple operation: I just take a clean kitchen towel or paper towel (to protect my hand from hot water vapor), and press down directly on each eggplant slice until it's completely flat. The result is a meaty, tender, and fully intact slice.
In an effort to streamline the process even further, I wondered if I could get the same effect out of the microwave. I can't fit an entire sheet tray in the microwave, so instead I placed a layer of eggplant slices sandwiched between paper towels on a large plate, placing a second large plate on top. By stacking another layer of eggplants and a third plate on top of that, I was able to fit a full eggplant's worth of slices in the microwave at the same time.
I zapped them for three minutes and checked the results. Even better than in the oven.
A microwave works by causing water molecules to rapidly flip back and forth. The resultant friction cooks your food. Microwaves can penetrate deeply into solid matter much faster than heat can (which is why microwaved foods cook so much faster), but in general, the denser and thicker the food, the less penetration a microwave will get. Dense, relatively dry items, like, say, your sister's My Little Pony dolls can take a long time to heat up (not that I know through personal experience). On the other hand, porous and moist slices of eggplant are microwave gold, cooking evenly and rapidly.
In under ten minutes, I had all three eggplants I needed to fill my casserole dish fully purged, pressed, and ready-to-bread.
Born to Bread
We're up to phase two of eggplant parm, which for most people, is the scariest. There's an irrational fear of frying, and I can never figure out exactly what it is.
Is it the mess? If you're careful, use the right equipment, and follow the right procedures, it's hardly any mess at all—certainly less splatter than, say, searing a steak. Is it a fear of fat? Well, that's a legitimate fear, I suppose, and one we'll address in a bit.
For me, the most annoying part of breading foods is accidentally breading your fingers as you do it. Standard breading is to dredge in flour, dip into beaten eggs, then coat with breadcrumbs. The flour helps the egg coat the food evenly (kinda like paint primer), which in turn lets the breadcrumbs stick. I've always heard the advice "Use one hand for dry and one hand for wet."
Does anyone else have trouble figuring out exactly what this means? Just by the nature of breading, doesn't one hand have to transfer things from one bowl to another, thereby violating the dry-wet rule? Do you pass it between hands in between bowls?
To clarify this matter, I asked Robyn to do a little doodle:
Here's what's going on:
- Using your right hand, pick up a slice of eggplant and transfer it to your bowl with flour. Scoop up some flour and toss it on top of the eggplant slice, tossing everything around until it's nicely coated.
- Still using your right hand, pick up the slices from the flour, shake'em a bit to get rid of the excess, and drop them into the egg bowl. This time, use your left hand to move the eggplant slices around until they're well-coated.
- Still using your left hand, pick up the eggy slices, let'em drip a bit, then drop them into the bowl with the bread crumbs. Here's the tricky part: If you now use your right hand to pick up the eggplant slice and flip it, you'll get bread egg on it. Use your left hand, and you end up coating it in bread crumbs. Here's the trick: use your right hand to pick up extra bread crumbs from around the eggplant and drop them on top. Carefully spread them around until you can pick up the slice without egging your hand. Flip the eggplant, and repeat, pressing into the crumbs to coat the eggplant thoroughly. It pays to have more bread crumbs than you need in the bowl.
- Pick up the eggplant slice with your right hand and transfer it to a plate, ready to be fried.
Phew! By the way, slicing eggplants lengthwise minimizes the number of pieces you have to bread. Mixing it up with pieces cut crosswise and lengthwise lets you make fun angry eggplant faces.
But that's neither here nor there.
The Myth About Frying
You often hear that fried foods absorb less oil if you make sure your oil is hot enough before you add the food to the pan. The rationale is that the force of the water evaporating and expelling itself from inside the food will keep the oil from entering it. This makes a little sense, but unfortunately, it's completely untrue.
You can quite easily prove that in reality, the exact opposite is case: the hotter your frying oil, the more oil your food will absorb.
I fried two batches of eggplant slices in oil at 375°F and at 300°F, weighing the amount of oil in the pan before frying and at the end in order to gauge how much was absorbed by the eggplant. The eggplant cooked in hot oil absorbed about 14% more, even though their total cooking time was significantly shorter (I cooked both to the same shade of golden brown). Given identical cooking times (by which time the hot oil version was overcooked), it ended up absorbing nearly 20% more oil. Why is this?
You see, once the eggplant has been purged of air, there's really not much free space left either inside the eggplant itself, nor in the breading. In order for it to absorb any oil, space must first be freed up. Where does that space come from?
Evaporating water. As water converts to steam and bubbles out of the eggplant, oil seeps in to take its place. The hotter the temperature, the more evaporation occurs, and the more space is left for oil to seep in. It is true that the force of the vapor leaving the food can keep some of the oil out, but the instant you remove the food from the hot pot, that pressure immediately drops and oil on the surface of the food quickly gets sucked into the air spaces within it.
In fact, about 70% of oil absorption in fried foods occurs right after you pull it out of the fryer (one of the reasons its essential to blot excess oil from fried foods as soon as it comes out)
So does this mean you should fry foods at a lower temperature? Absolutely not. Here's the interesting thing: even though food fried at a higher temperature has more grease in it, it actually tastes less greasy. That's because the feeling of greasiness in the mouth has less to do with the actual amount of grease on the food, and more to do with the combination of grease and liquid. Greasy is the feeling of soggy food with oil on it.
As far as actually cooking the slices go, I found that shallow frying them in a wide skillet was easier, less messy, and easier to clean up than actually deep frying them. I also used panko-style crumbs which I seasoned myself—far easier than making your own, and much better than the sandy "Italian-style" crumbs from the supermarket.
When all is said and done, the cross-section of your eggplant slices should look something like this: crisp and golden brown, with a dense, meaty, fully-cooked interior.
What's that? You mean after I've done all that I still have to make sauce, grate cheese, assemble, and bake this sucker?
That's right, young grasshopper: You gotta pay your dues if you wanna sing the blues.
Luckily, I've already got a pretty good procedure down for making a killer tomato sauce. Based in a large part off of Marcella Hazan's simple tomato sauce recipe, the key is to use a combination of butter and olive oil, and to add onion flavor to the pot without ruining its texture by simmering a halved onion in the sauce while it reduces.
As far as cheese goes, I used a mixture of mozzarella and Parmigiano-Reggiano (which I added to the breading, sprinkled in between layers, and dusted on the final dish after it came out of the oven—Di Fara style—for a triple whammy or flavor).
Fun Fact: Despite the fact that the dish is called Eggplant Parmigiana, it actually has nothing to do with Parma, the city in Emilia-Romagna that produces both Prosciutto di Parma, and Parmigiano-Reggiano. Depending on who you ask, the name comes from either its use of parmesan cheese, or from the Sicilian word parmiciana, a reference to the shutter of a window, and how the eggplants overlap each other like slats of wood. I'll leave it to the Italians to fight over their etymology.
I've got more important things to do. Like eat more vegetables. Also, to figure out a way to use the word "egg-pants" in this story. Any help?