Low carb smash burgers with a crisped, crunchy edge and juicy 80/20 beef, 0g net carbs, and 26.7g protein. I smash them thin and loose-packed on a screaming hot surface, so the crust makes the bun completely optional.
I started smashing burgers a few years ago and I have not gone back to thick patties since. The technique is simple but the result is completely different from a regular burger. You take loosely formed balls of 80/20 ground beef, press them flat on a hot surface, and the fat renders out against the heat to create a crust that almost crackles when you bite into it. That crisped edge is the whole point. The bun just gets in the way of it.
The key is how you handle the meat. I don’t pack my burger balls tight. I want the strands loose, barely holding together, because that’s what gives you a juicy interior once it hits the heat. If you compress the beef like you’re making a meatball, you lose the texture that separates these from regular thick patties. Loose strands, hot surface, one hard press. That’s it.
I’ve made these on the grill and in cast iron, and both work. On the grill at 450-500 degrees, you get great char and a little smokiness. In a cast iron skillet, the crust comes out darker and crispier because the flat surface gives you full contact. I go back and forth depending on the weather, but cast iron has become my default for weeknight dinners. If you like cooking over fire, my grilled keto burger uses a thicker patty with horseradish sauce, and the grilled dry aged tomahawk steak is what I pull out when I want to go all out on the grill.
For seasoning, I keep it to steak seasoning and salt. Nothing fancy. The beef does the work. I season both sides after smashing, not before, so the spices hit the surface right where the crust forms. If you want a solid low carb burger recipe that takes 13 minutes start to finish and tastes like you put in real effort, this is it.
We eat these without buns most of the time. I’ll pile them on a plate with pickles, mustard, sliced cheddar, and sometimes a few avocado slices. My son ate two patties straight off the pan without asking for bread once. If you want something to hold, butter lettuce works as a wrap, and a bun works too. I also love pairing grilled nights with keto grilled pork chops or throwing a keto grilled pizza on alongside for variety.
Smash patties are thin and crispy by design. When I want the opposite, thick and stuffed with a molten cheese center, my juicy lucy burger is the other burger in my rotation.
For meal prep, I roll the balls and freeze them raw. Pull them out the night before, thaw in the fridge, and smash fresh from cold onto a screaming hot pan. Smashing them flat before they go in the freezer kills the crust. You want that cold ball hitting hot metal so the fat sears on contact. I usually get a week’s worth of lunches out of a double batch.
Stacked with all the fixings. These go great with my keto french fries.
Loosely formed balls. There is no need to smooth or round off the edges, those loose ends get crispy.
I smash the balls before they hit the grill so loose bits of beef do not fall through the grate.
Cast Iron on the Grill for Crispy Edges
If you want crispier edges, set a cast iron skillet on the grill and cook the patties in the skillet. The fat stays in the pan instead of dripping through the grate, and that fat crisps the outer edges of the patty.
Which Ground Beef to Buy
Prepacked grass fed ground beef is usually pressed together too tightly for smash burgers. You need a loose grind. If grass fed beef matters to you, buy grass fed chuck and short rib and have the butcher grind them together, or grind them yourself at home.
I season both sides with salt and a steak seasoning made with garlic, coriander seed, paprika, fennel, rosemary, pepper, thyme, and parsley.
My favorite toppings are mayonnaise, mustard, ketchup, lettuce, pickle, tomato, and red onion, and once in a while a fried egg.
How to Make Smash Burgers in Cast Iron
If you don't have a grill or just prefer cooking indoors, cast iron is my preferred method. Heat your skillet over high heat for at least 5 minutes until it's smoking. Drop a cold, loosely packed ball of beef onto the dry pan and press down hard with a sturdy spatula or burger press. One firm press, then don't touch it. Let the crust develop for about 2-3 minutes before flipping. The bottom should release cleanly when it's ready.
I don't oil the pan. The 80/20 fat content handles it. Season after smashing so the steak seasoning and salt sit right on the cooking surface. Flip once, add cheese with about a minute left if you want it, and pull them after another minute or two. The whole cook takes under 5 minutes per burger. If you like the smash-and-sear technique, my grilled flank steak uses the same screaming-hot approach, and my low carb smashed dumpling tacos take the press-and-crisp idea in a completely different direction.
Preheat grill to 450 to 500 degrees F. Divide ground beef into 6 equal portions.
2
Form burger balls
Grab one portion of ground beef at a time and loosely form it into a ball. Do not firmly pack it into a ball. You want the strands to still be loose for the juiciest burger. Set aside on a flat surface or parchment paper. Repeat with other portions of hamburger meat.
3
Smash burgers
Place a piece of parchment paper over the patties. Then give each patty a whack with the palm of your hand, smashing the burger down. Remove the parchment paper. See instructions below for cooking burger patties in a cast iron skillet on the grill.
4
Season with salt
Sprinkle each side of the patties with steak seasoning and salt.
5
Grill
Spray the grill with cooking oil spray or wipe the grate with a paper towel dipped in oil. Use tongs to wipe the grate with the oiled paper towel. Place patties on the grill and grill over direct heat. Cook until desired level of doneness. Rare: cook for about 4 minutes (125 F); Medium-rare: cook for 5 minutes (135 F); Medium: cook for 6 to 7 minutes (145 F); Well-done: cook for 8 to 9 minutes (160 F). Flip the burgers halfway through cooking. If desired, add cheese when you have about 1 minute left of cooking.
Nutrition
Per serving: 1 burger
Calories
387
Fat
30.7g
Protein
26.7g
Total carbs
0g
Net carbs
0g
Nutrition is an estimate calculated from the ingredients listed. Brands vary, so check labels if you track closely.
Frequently Asked Questions
What cheese works best on these?
I use cheddar most of the time. It melts fast in that last minute of cooking and has enough flavor to stand up to the crust. American cheese works if you want that diner-style melt. I've also done pepper jack when I want some heat. The trick is adding it when you have about a minute left so it gets about 60 seconds of direct heat to melt down over the edges.
Do I need a burger press to smash these?
No. I press with the palm of my hand, and the parchment paper is what makes that work. It keeps the beef from grabbing onto your hand or a flat spatula, and it peels right off. Press once and stop. A second press squeezes out the juices.
What can I use instead of steak seasoning?
I mix garlic powder, onion powder, paprika, and black pepper when I'm out of my usual steak seasoning. About a teaspoon of each for two pounds of beef. I've also gone with just coarse salt and fresh cracked pepper when I want the beef flavor front and center. The simpler the seasoning, the more the crust does the talking.
How do I reheat leftovers?
I throw them back in a hot cast iron skillet for about a minute per side. The crust crisps right back up, which is the whole advantage of thin patties over thick ones. Microwaving works in a pinch but you lose that crunch. I store mine in an airtight container in the fridge for up to 3 days, and the steak seasoning holds up through reheating better than most burger seasonings I've tried.
I grill them hot, loose balls, done in a few minutes, and I get lunches for the week out of one batch. I cook all six Sunday and the crust still holds up reheated in a dry pan on Wednesday!!!
Stopping mid-reach is the review I needed. The steak seasoning at that temp toasts into the sear instead of just sitting on the surface, that’s where the smell comes from. Glad it got you, Joanna.
26.7 grams of protein is what stopped me mid-scroll and made me actually read this recipe. I pre-mix the steak seasoning in bigger batches now and keep it in a jar by the stove, cuts the prep down to practically nothing on a weeknight. Tried something on my last batch: pressing a small cube of cold butter into each ball before smashing. The fat melts out as the crust forms and you get this browned-butter edge on the outside that cooking spray just doesn’t give you. Same crust, richer somehow. Four batches in and I’m not going back.
Cold butter in the ball, not brushed on after. The timing is the whole difference. Fat’s browning inside the sear instead of sitting on cooked meat. Trying this next batch, Marcus.
Burger nights were the thing I missed most on keto, and it wasn’t the bun. Just… the whole thing felt gone. Every bunless burger I’d made before tasted like I was pretending. This one doesn’t. Getting the grill to 500 and that crust on 80/20 beef, ‘bun optional’ is actually true here.
That’s the word for it. I tested this with leaner ground beef when I was developing it and it doesn’t crust the same way, even at 500. The fat is the other half of the equation.
Third time this week. Batch two I pulled the parchment too early and the crust came right off with it. Four stars only because I always tell myself one patty and then eat two.
I mixed a tablespoon of Worcestershire into the beef before forming the balls, just curious what it would do, and the savoriness came up a full notch without touching the texture at all. The smash still gave those crispy, crunchy edges the recipe is built around, but there was noticeably more depth in every bite. Made it both ways back to back this weekend to make sure it wasn’t in my head. It wasn’t. Adding this to the summer grill rotation for sure.
Side by side is the only real test. One tablespoon threads right into the steak seasoning without taking over. Two would probably push it into steak sauce territory.
Tight packing squeezes the air out before it ever hits the pan. I keep mine barely holding together for the transfer. Hope the next batch crackles, Lindsey.
Tried smash burgers twice before on a cast iron and they were never worth the cleanup. The grill at 450 with the parchment paper smash gets a crust on the edges I haven’t managed any other way. This is the one.
Cast iron has to be smoking before the beef hits it. Mine takes a solid 5 minutes on high before I drop anything. The grill just gets there on its own.
Mixed a splash of Worcestershire into the beef before forming the balls and honestly that extra kick on the seared crust is SO worth it. Tiny change but you notice it immediately. Steak seasoning alone is great, I just can’t go back now.
I’ve had a cast iron smash burger method I’ve been using for two years and this just replaced it. The crust you get at 500 degrees on the grill is different from what I was getting on the stovetop, more even browning across the whole patty instead of just the center contact points. Loose-packing matters more than I thought. Not going back.
The loose-pack method genuinely changes the crust situation (way more contact, way more crunch). One thing worth passing on: parchment paper started scorching at 500 degrees, so I switched to pressing with a bare spatula and it held up better. Everything else landed exactly how I wanted.
I kept wanting to pack the meat tighter because loose felt wrong, but I went with it. That crisped edge was the payoff. First time doing smash burgers (had to read the smashing step twice before I felt okay doing it) and mine came out a little uneven but the seasoning and crunchy crust were there. 500 degrees and a parchment square and now I get why people swear by this. Back at it this weekend.
Loose pack is the one thing most people fight. Uneven shapes don’t matter – crust is the same either way. Weekend batch will be faster once your hands know the smash pressure.
I’ve been making smash burgers at home for a couple years, tried everything from cast iron to a flat top attachment, and kept getting something that was fine but never had that diner-style crust I was actually after. Found this a few weeks ago, made it on the grill at 500, and there it was. The crust you get from that heat is just not what I was getting inside on a flat surface. Something about the grates at that temperature, the edges get this almost char-y caramelized crunch that makes the bun feel beside the point. The loose ball smash technique I’d been skipping too, convinced it didn’t matter. It does. The texture inside is different. These are the smash burgers I’ve been trying to make. Not going back.
500 on grates does something flat surfaces just can’t reach. That edge char is different. I still default to cast iron for weeknights but that grill version is the one I keep thinking about.
So I laid a slice of American cheese on the parchment before smashing (rogue move, I know) and now I can’t make these any other way. The cheese fuses right into that crust as it hits the hot grate, renders into those lacy edges instead of sitting on top and melting off, and the bottom of the patty ends up with this caramelized cheese-beef crust situation I was not ready for. I have been making smash burgers for years and this is something else entirely. One caveat: the grate has to be screaming hot, like the full 500, because at lower temps the cheese just sticks to the parchment and tears — that’s exactly what happened my first attempt before I figured out the timing. First spring cookout last weekend, made a double batch, and even going a little lighter on the steak seasoning than the recipe calls for (I had been heavy-handed my first run), these were so good that I’m just docking the one star for my own early mistakes. Worth the experiment.
My son has demanded a bun on every burger he’s ever eaten. Made these Sunday and he ate two patties straight, no questions asked. Something about that smashed, crisped edge makes the bun thing irrelevant.
We do Sunday meal prep to survive busy weeknights without ordering pizza, and smash burgers seem like a perfect fit. Can I roll the balls ahead of time and just smash them on demand through the week, or does the meat need to be fresh for the texture to work?
Roll and freeze the balls. Pull them out the night before, thaw in the fridge, smash fresh from cold onto a screaming hot pan. Pre-smashing kills the crust.
