01/05/2017
The Chemistry Of The Brassica Family
Have you ever cooked Brussels sprouts and out of the blue they have a bitterly taste? The chemical reaction is the same across the brassica family, including mustard seeds, radishes and cabbage.
Well done, roasted Brussels sprouts with a balance of sweet and savory, but nailing that perfect balance calls for a long stay in a hot oven.
Even then it can be a disappointment. Pile too many sprouts in the pan and they steam, turning mushy and dull. Let them go to long and they get dry and bitter.
Chopping, shredding or even chewing a sprout releases the enzyme myrosinase. That enzyme converts sulfur – containing compounds in the sprout into bitter tasting compounds. But heat neutralizes that enzyme – induced chemical reaction. Once the internal temperature of a sprout goes above 140° the marosinase is inactivated.
I was recently in a restaurant and had their charred Brussel sprouts with chili lime vinaigrette. They were both charred and tender, and bore little of the brassicas characteristic bitterness. You would think they had been roasted in a very hot oven. When in fact they had used a cast-iron skillet to accomplish in minutes what normally took a half hour or more. And did it much better. Cast-iron holds heat extremely well, and the more it holes, the more it can transfer to the food. That process happens more quickly_ and more intensely_than oven roasting, because air neither holds nor transfers heat efficiently.
I loved the way the searing hot skillet gave the sprouts a delicious char that I've never achieved in the oven. Chemistry again was at play. In the oven, the sugars in the Brussels sprouts caramelized, which occurs between 320° and 380° but the intense heat in the cast iron skillet pushes the surface of the sprouts to 400° or more, the temperature at which charring occurs. And with charring comes more intense flavors.
But after testing the theory a few times it wasn't long I discovered that size did matter, as well as how they were prepped. The larger sprouts didn't taste as good as small or medium ones. The larger sprouts contain a higher concentration of the compounds that lead to bitterness. The heat of the pan wasn't able to pe*****te larger sprouts quickly enough to migrate the process during the shorter cooking time. And even with a smaller sprouts, they were best cut in half, creating more surface area in contact with the skillet and therefore more charring.
I found that the dry skillet produced tough, dry sprouts. Adding oil definitely helped with that but not with the flavor. Just a tablespoon of extra-virgin olive oil made them tastier tender.
A simple sauce such as a bagna càuda, a warm garlic and anchovy infused dip from northern Italy_ is a perfect fit. The heat will neutralize the fishy flavors of the anchovies, yet preserve their salty, savory side. Minced garlic would stand up to the anchovies. The combination, plus red pepper flakes and a final splash of lemon juice, results in a rich, tangy dressing.
Adding a note of sweetness to soften the bitterness from the sprouts. It gives the sprouts a deeper color and flavor, thanks to the glucose and fructose in the honey. It also caramelizes faster than sugar. Leaving them much moister. But why?
Honeys hydroscopic nature, or tendency to attract water molecules. Caramelized honey loses its water content, but the final drizzle of honey in the dressing at the end locks in moisture and makes the sprouts tenderer.
The final dish is a meaty flavor, nutty texture with bright notes of the best Bussell sprouts you will ever taste and accomplished in minutes.
Charred Brussels Sproupts
25 minutes/Serves 4
A well-seasoned cast iron pan, stainless steel doesn't hold the heat well enough to properly char. The pan needs to be at least 12 inches. Toss in the sprouts with oil and honey before cooking prevents them from drying out. Use small to medium sprouts.
Don't omit the anchovies. You may not like them, but as they cook they fade into a rich, salty background flavor.
1 pound small to medium brussels sprouts, trimmed and halved
4 tablespoons extra-virgin olive oil
4 teaspoons honey
Kosher salt
4 garlic clothes, minced
4 anchovy fillet's, minced
Red pepper flakes
2 teaspoons lemon juice
In a large bowl, toss the sprouts with 1 tablespoon of oil, 2 teaspoons of honey and a half teaspoon of salt. Set aside.
In a 12 to 14 and cast iron skillet, combine the remaining 3 tablespoons of oil, the garlic, anchovies and a quarter teaspoon of pepper flakes. Set oven high heat and cook, stirring occasionally, until the garlic begins to color, 3 to 4 minutes. Scrape the mixture, including the liquid, into a bowl and set aside..
Return the skillet to high heat. Add the sprouts and use tongs to arrange them cut side down in a single layer. Cook, without moving, until deeply browned and blackened in spots, 3 to 7 minutes, depending on your skillet. Use the tongs to flip the sprouts cut side up and cook until charred and just tender, another 3 to 5 minutes.
As they finish, return the sprouts to the bowl and toss with the garlic mixture, the remaining 2 teaspoons of honey and a lemon juice. Season with salt and pepper flakes.
