A Hamburger Today
The Food Lab: Really Awesome Black Bean Burgers
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Even in my earlier days as an unabashed eater of all things ground and beefy, I always had a place in my heart for black bean burgers. I'd occasionally sneak one off of my vegetarian friends during backyard barbecues. If a bar claimed to have excellent homemade black bean burgers, I'd order one (with cheese and bacon, if I felt like it). In its ideal form, a black bean burger should be moist and meaty, with a patty that holds together and forms a substantial crust, packed with robust bean flavor and the seasonings that complement it.
Scan your way through the internet or the cooking section at the book store and you'll find recipe after recipe for black bean burgers that follows the same basic procedure: Chop your black beans in a food processor along with some aromatics; stir them together with eggs, breadcrumbs, and some more whole or partially chopped beans; form them into patties, and cook. I've followed a half dozen of these recipes, and while most of them produce pretty good flavor, they all have one fatal flaw: mushy texture.
I mean, how could they not? They're essentially made up of mashed beans and egg.
So what's the secret to black bean burger patties that have textural variation and nuance to match their great flavor? I had to cook my way through a few dozen to figure it out.
I like to iron out small problems before addressing the larger ones, so I decided that I'd start by nailing down a flavor profile I'd be happy with before addressing the issue of texture. Some black bean burgers go full Southwest on you, with chili powder and cumin. I wanted my burgers to be a little more neutral in flavor, so I opted to leave out the spices. Instead, I settled for a mixture of onions, garlic, and poblano peppers (you can use bell peppers if you don't want any heat).
Mixing them straight into the patties results in an undesirable steamed onion flavor. Instead, I sauté all the vegetables in oil until they're soft before incorporating them into the patty.
Chipotle peppers packed in adobo might be so common in black bean recipes that it borders on tacky to include them. But you know what? I've loved them ever since I was kid, and when used the right way, they can add just the right amount of smoky, savory flavors without overwhelming the burgers or pushing them all the way into Southwestern territory. I found that a single pepper for two cans of beans was just the right amount.
I formed my patties using the standard method: pulsing half of the beans in the food processor until pasty, them folding in the sautéed vegetables, an egg, the chipotle pepper, and some breadcrumbs (panko provide the best texture), seasoning the mixture before forming it into patties and grilling it. As expected, the flavor was fine, but here's what we got inside:
Time to get to work on that.
Beef vs. Beans
So here's a question for you: Why does a black bean burger behave so differently from a ground meat burger when you apply heat to it? Cook a hamburger and it changes from being mushy and soft to having a wide variety of textures, with an interior that clings together in springy, juicy clumps, interspersed with pockets of rendered fat and juicy meat. Cook a black bean burger and you may develop a crust on the exterior through dehydration, but the interior remains largely the same: soft, mushy, and uniform.
This is because a black bean burger patty is made up of already-cooked ingredients. Raw meat has long, sticky proteins that cling together. As a meat patty cooks, those proteins remain entangled while contracting and changing shape. This is what creates that springy and juicy texture. On the other hand, a black bean patty is made up mostly of starch and proteins that have already been cooked once. They no longer cling together in the same way and don't really change shape when you cook them for a second time (ever notice how a black bean patty doesn't shrink on the grill the way a meat patty does?)
Eggs can help mitigate this to a degree—they are a source of raw proteins that help to bind the chopped beans together as they cook—but they never get as firm or sticky as an entire patty of raw meat.
What does this mean for our burgers? It means that we have to build that texture into the patty mixture right from the start.
Filling 'er Up
So what textures am I looking for here? Just like in a meaty patty, I want a mix of hearty, robust bits interspersed with tenderness, along with juicy pockets that burst with flavor. I ran through the usual gamut of add-ins: cooked grains like barley, bulgur wheat, wheat berries, and farro, as well as nuts including peanuts, macadamia, pistachio, walnuts, and pine nuts. The victor in the end? Chopped cashews.
When cooked in a moist environment, they soften up to the point that they offer just a bit of pleasing resistance to each bite, but quickly give way as you start to chew. Their flavor is also mild enough that they don't distract from the bean flavor I wanted highlight.
For the flavorful eruptions of moisture, I knew that I wanted to add some extra fat. A couple of tablespoons of mayonnaise helped, but it was more of an overall moisture-booster, rather than the concentrated pockets I was looking for. What about cheese? I figured grated or crumbled cheese might work: it'd keep its shape until the burger is hot enough to melt it, whereupon it'd soften up into just the kind of fatty, flavorful burst I was looking for.
Semi-soft melting cheese like cheddar, jack, and muenster all worked well on the flavor and juice fronts, but they were a bit of a pain to cook (the melted cheese would drip into the grill or the skillet). They were also a little too gooey. Incorporate them into the patty and you no longer had a black bean burger; you had a black bean-cheddar burger or a black bean-jack burger.
Instead, firmer, fresh cheese proved just the ticket.
Both cotija and feta cheeses provided exactly the right salty, moist, textural variance I was looking for. Combine the cashews, mayo, and cheese with the original burger and you get this:
Texture-wise, it's a good step above every other recipe I'd tried, but it still wasn't quite there—I was still encountering that unpleasant mushiness between the chunkier bits.
Perhaps the problem was with the black beans themselves.
Up until now, my treatment of the beans had been no different than any other recipe: mush half and fold in the rest, the idea being to offer some textural variation. The problem is, even whole cooked beans are still kinda mushy. So the question is: how do we get our beans less mushy?
I tried starting with dried beans and boiling them, halting the cooking while they were still a little shy of done. That didn't work. Undercooked beans don't taste good, no matter what you're going for (I also wanted to avoid having to cook beans from dry in what should be a relatively quick and easy recipe).
Instead, I remembered the recipe for a Roasted Chickpea and Kale Salad I developed last month and noted how baking canned beans can turn them dense and meaty without rendering them inedible.
I spread a couple cans of drained beans onto a baking sheet and tossed them into the oven. Thirty minutes later, here's what emerged:
They don't look too pretty, but I popped one into my mouth. The transformation is incredible. They go from soft and mushy to dense, meaty, and packed with intense black bean flavor.
I tossed them into the food processor to grind them up for burgers.
After combining them with my egg, aromatics, breadcrumbs, cashews, and cheese, I formed them into patties and seared off a few in a cast iron skillet.
Cutting them open, here's what I got:
Check out that texture! Biting into them, they're as tasty as they look. Tons of bean flavor, plenty of juicy, salty pockets of cheese, and a texture that is tender but not a bit mushy. Black bean burger nirvana, if such a state exists.
Now listen: these burgers are plenty meaty in texture and flavor, but there are two important things to remember: First, they don't taste anything like a beef burger, nor are they meant to. They are a delicious thing-to-stick-in-a-bun all on their own. Second, they don't cook the same way beef burgers do because, well, they're not beef burgers.
The biggest trick to cooking them is to use moderate heat. A beef burger wants to be cooked in a ripping hot skillet or a blazing inferno on the grill to get some nice charring on the exterior before the middle has a chance to overcook. Do the same with a bean burger, and you end up with a blackened-on-the-outside, raw-egg-in-the-middle hockey puck.
Don't go for anything more than medium heat in a skillet or a moderate flame on the grill.
Each method offers its own advantages. In the skillet you can get a much deeper, more evenly crisped and browned crust, while the grill produces those smoky, charred flavors that adde even more meatiness to the mix.
If you're going the grill route, brush the patties with oil before placing them over the heat. This oil acts as a buffer, helping them to brown more evenly while preventing them from sticking to the grates.
Cheese is not a must, but it's hard to resist.
Any good melting cheese like American, cheddar, jack (pepper jack if you'd like) or—my new favorite—muenster works. Just make sure you get it on there with enough time for it to fully melt and optimize that goo factor.
As for toppings, the sky's the limit. I have to admit: I gave in and went full Southwest a couple of times with pepper jack cheese and a dollop of guacamole, but most of the time I like to stick with the classics: shredded lettuce, pickles, and onions, and—aw, who am I kidding?—since I have those chipotles out already, some chipotle mayonnaise.
The best thing about these burgers? I consider beef burgers to be an only-when-I'm-ready-to-go-into-food-coma treat. These, on the other hand, are hearty, but not heavy: they're the kind of burger I can eat whenever I feel like it. It's a good thing too, because considering how tasty they are, that's going to be pretty darn often.
About the author: J. Kenji Lopez-Alt is the Chief Creative Officer of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.