Alright, here we go. Vibrantly purple eggplant without deep-frying.
As I mentioned in my previous post about this (which I've updated with a note and my technique changes), the theory goes that exposure to air (oxygen specifically?) while cooking is what turns eggplant skin brown. Although I was skeptical at first, my subsequent trials with different methods have led me to believe that it may be so. In particular, when I tried covering eggplant while frying it skin side up in my wok, it seemed still to be purple until after I lifted the lid and fresh air started circulating over the eggplant. And I guess with microwaving, maybe not enough is shut in with the eggplant when you close the door for it to turn brown. ? But clearly there is air shut in with the eggplant both when microwaving or covering to steam. Could be the amount matters.
In any case, I've found that frying in some amount of oil does indeed seem to be the most effective and efficient way to keep your eggplant purple when cooking. But you don't have to commit to using the massive amount of oil needed for deep-frying! I found that shallow-frying actually works very well, too, though it seems like you get a bit of browning from contact with the hot wok. And I also tried shocking in ice water after frying--and found it to have no discernible effect at all. Don't bother.
Pictured in my trials below, besides the with/without ice shock, I also tried with/without the 15 minute salt water brine. Unsoaked eggplant seems to end up slightly prettier--less wrinkly, more purely purple--but I prefer the brined eggplant because it absorbs less oil and thus has better flavor and texture. (Unbrined is a bit of an oil sponge.)
Above: all were brined, but left side (vertically oriented) had the post-frying ice shock while the right side (horizontally oriented) did not.
Below: none were brined, but the right side (vertically oriented) had the post-frying ice shock while the left side (horizontally oriented) did not.
So, the upshot is if you want purple eggplant but don't want to use so much oil as deep-frying requires, shallow-fry instead, making sure you cook skin side down (as you would deep-frying, too). If you don't mind the amount of oil needed to deep-fry (maybe you're going to fry other things), deep-frying will get you slightly prettier results in that shallow-fried eggplant browned a bit where it touched the wok.
[Update: The other benefit of deep-frying is that you can cut the eggplant into other shapes an not be constrained by need the skin to all be in contact with a relatively thin layer of oil. Namely, you can roll cut the eggplant and still have beautiful purple skin like at this restaurant:]
Also, once you've fried your eggplant, when you add it back into the wok to coat with sauce, don't keep cooking over a high heat or the skin will continue it's browning progress.
Pictured at the top of this post and below is actually my yu xiang (fish fragrant) eggplant with pressed tofu variation of the dish. Pre-pressed tofu is actually super convenient, and I'll write it up in a future post.* Recipe (nearly the same, but adjusted for the tofu inclusion) is below.
*Thanks in large part to the tofu vendor at the weekly farmers market, which sells pre-pressed plain and five-spice tofu, fried tofu, and fresh tofu (as well as soy milk and dou (fu) hua), I've lately become a half-time vegan/vegetarian. It's just so convenient!
“Fish Fragrant” Eggplant Yu Xiang Qie Zi - with Pressed Tofu
1 lb. Chinese or Japanese eggplants (about 2 large Chinese ones--Japanese eggplants are smaller), trimmed, split into quarters lengthwise and cut into 3- to 4-inch lengths
8 oz. pressed tofu (should come pre-pressed, so no need to press it yourself), cut into long blocks similar in dimensions to the eggplant
Peanut or vegetable oil for shallow frying
6 dried red Chinese chilies, sliced, seeds discarded (or Thai bird chilies, any small hot red chili)
~1-inch knob ginger, minced (about 1 TBS)
4 medium cloves garlic, minced (about 4 tsp)
4 scallions, whites thinly sliced, greens cut into 1/3-inch segments (keep scallion whites and greens separated)
2 TBS Sichuanese chili broad bean paste (doubanjiang)
1 TBS rice wine for cooking
½ TBS sugar
2 scant TBS soy sauce (gluten-free or tamari)
2 TBS black or chinkiang vinegar (use a not-too-fancy balsamic vinegar in its place if unavailable)
1 tsp tapioca starch (or corn starch)
1 tsp water
Roughly chopped fresh cilantro leaves, for garnish
- Combine 6 TBS salt with 6 cups water in a very large mixing bowl (1 TBS salt per cup of water), stirring to dissolve the salt. Add eggplant pieces, skin-side up, and set aside to soak for about 15 minutes. If that’s not enough salt water, add more in the same ratio until all your eggplant has exposure to the brine.
- In a small bowl, combine rice wine, sugar, soy sauce, and black vinegar. Set sauce aside. In a separate small bowl, combine tapioca starch and water. Drain eggplant and spin dry in a salad spinner or pat dry with paper towels.
- Heat ¼-inch of oil in a wok over medium heat until inserting chopsticks into the oil produces small bubbles energetically. Add eggplant in a single layer, skin side down. Cook for about 2 minutes. Remove eggplant from wok and set aside in a bowl while you cook the next batch of eggplant.
- Pour out excess oil (leaving about couple TBS worth in the wok) into a heat-proof container to discard (or add back as needed). Add pressed tofu to wok and fry until lightly browned on one side, flipping to brown on the reverse side before continuing.
- Push tofu to side of wok (or remove from wok) and add ginger, garlic, scallions, and chilies to the wok. Cook, stirring constantly until fragrant, about 30 seconds. Add broad bean paste and stir until fragrant, about 30 seconds. Toss tofu with the ginger, garlic, scallions, chilies, and broad bean paste. Pour the sauce mixture over the tofu in the wok, toss and cook for a couple minutes to allow the tofu to absorbe some of the sauce.
- Turn the heat down to low and add the eggplant back into the wok along with the scallion greens. Give the starch slurry a stir to make sure the starch isn’t caked at the bottom of the bowl before pouring over the contents of the wok.
- Cook, tossing constantly, until sauce is thickened, glossy, and coats eggplant. Unless you've added too much fluid, this should happen quickly. If the sauce over-thickens, thin with a few tablespoons of water. Transfer the contents of the wok to a serving bowl, garnish with chopped cilantro leaves, and serve immediately with freshly steamed rice.