Blackstone Mushroom Swiss Smash Burgers (The Crispy-Edge, Buttery-Mushroom Recipe I Cook on Repeat)

If you own a Blackstone, the mushroom Swiss smash burger is the recipe that earns the griddle its place on the patio. It’s the burger that converts skeptics — the friend who “doesn’t really like mushrooms,” the kid who asks for “plain cheese only,” the neighbor who thinks his charcoal grill is superior. One bite of a paper-thin, ragged-edged, Maillard-crusted patty topped with garlic-butter mushrooms and a slow-melting blanket of Swiss, and the argument is over.

I’ve been cooking smash burgers on my Blackstone every other weekend for about four years now. I’ve ruined a few. I’ve nailed a lot. Below is the exact method I land on every single time — temperatures, timing, ingredient ratios, the fixes for the three things that go wrong most often, and the small details (American under the Swiss, garlic-Worcestershire-thyme mushroom finish, mayo on the bun before toasting) that elevate this from a decent burger into the one your guests will text you about.

This is the long version. Skip to the recipe card at the bottom if you just want the numbers. Otherwise, settle in — I’m going to teach you why smash burgers work and how to make these perfect on a Blackstone every time.

Why Smash Burgers Belong on a Blackstone

Smash burgers exist for one reason: maximum crust. When you smash a 2-ounce ball of beef onto a 425°F flat top, three things happen at once.

The fat renders instantly and pools under the patty, frying it. The exterior proteins and sugars hit the Maillard reaction temperature in seconds, building that lacquered, deep-brown, almost-burnt-in-spots crust that’s the entire point of the burger. And the patty cooks through in under two minutes — so the interior stays juicy while the edges turn into bacon-adjacent crispy bits.

You cannot get this on a grill. Grates have gaps, fat drips through, you lose the rendering. You cannot easily get this in a skillet either, unless the skillet is very large and you’re cooking one burger at a time. The Blackstone gives you 36 inches of cast iron-equivalent surface that holds heat, runs hot, and lets you smash four or eight patties at once with room left over for mushrooms, onions, and toasting buns. It is the perfect tool for this exact recipe.

What Makes This Recipe Different

Most Blackstone mushroom Swiss burger recipes online get the basics right and stop there. Here’s where this version goes further:

• Two layers of cheese. A slice of American melts under a slice of Swiss. The American is for melt and creamy texture (it’s an emulsified cheese — it pools rather than separates); the Swiss is for flavor and that signature nutty, slightly funky note that makes a mushroom Swiss burger taste like a mushroom Swiss burger. Steakhouses do this. I copied them.
• The mushroom finish. Most recipes saute mushrooms in butter and call it done. I finish mine with minced garlic, fresh thyme, a glug of Worcestershire, and a final pat of butter off-heat. The result is mushrooms that taste like they came off a $26 pub burger.
• 80/20 beef, not 90/10. Lean beef is the wrong choice for smash burgers. You need fat to render and lubricate the patty against the griddle. 80/20 is the floor. 75/25 is even better if your butcher will grind it for you.
• The double-smash. I smash hard once, immediately, and never again. The single press in the first 10 seconds is what creates the crust. Pressing later just squeezes out the juices that should stay in the burger.
• Mayo on the buns before toasting. Butter is what every recipe tells you to use. Mayo crisps better, browns more evenly, and doesn’t burn as quickly. Try it once and you won’t go back.

Ingredients Needed

• 80/20 ground beef — Juicy beef with rich flavor and fat
• Kosher salt — Enhances meat flavor and natural beef taste
• Fresh cracked black pepper — Adds bold heat and subtle sharp bite
• Garlic powder — Deep savory garlic flavor throughout each patty
• Onion powder — Sweet savory backbone that rounds out flavor
• Cremini mushrooms — Earthy mushrooms with deep meaty umami flavor
• Salted butter — Creates rich silky coating for mushrooms
• Minced garlic — Strong aromatic flavor that boosts savory notes
• Fresh thyme — Light herbal flavor that brightens mushroom mixture
• Worcestershire sauce — Tangy umami sauce that deepens savory richness
• Kosher salt — Balances flavors and enhances mushroom savoriness naturally
• Black pepper — Mild heat that sharpens earthy mushroom flavor
• Extra butter — Finishes sauce with glossy rich texture
• Brioche buns — Soft sweet buns with rich buttery flavor
• American cheese — Smooth melting cheese with creamy mild taste
• Swiss cheese — Nutty cheese with excellent melt and texture
• Mayonnaise — Creamy spread that adds moisture and tang
• Shredded lettuce — Crisp fresh crunch for texture and balance
• Red onion — Sharp bite with crisp fresh onion flavor
• Dijon mustard — Tangy mustard with bold sharp flavor kick
• Garlic aioli — Creamy garlic sauce with rich savory finish

A few ingredient notes worth your time:

Cremini over white button. Creminis are just immature portobellos. They have meaningfully more flavor than white buttons for almost the same price. Use them.

Don’t wash mushrooms. Wipe them with a damp paper towel. They’re sponges. Submerging them in water makes them weep on the griddle and steam instead of brown.

80/20 vs 90/10. I said it above and I’ll say it again because it’s the most common mistake. 90/10 beef makes a dry, sad smash burger. The fat is the cooking medium and the flavor.

Salt the patties on the griddle, not in the bowl. Salt in advance pulls moisture and starts curing the meat. You want a tender, loose patty. Form the ball, smash it, then season the top.

Equipment You’ll Want

• A Blackstone griddle (any size; my recipe is sized for a 28″ or 36″)
• A sturdy burger smasher or stiff metal bench scraper. I use a 6-inch round cast iron smasher. A heavy spatula works in a pinch but doesn’t give you the leverage.
• Parchment paper squares (about 4×4 inches). Place between the smasher and the meat — this prevents the patty from sticking to your smasher.
• A thin, sharp-edged metal spatula for scraping the patties off the griddle without losing the crust.
• A surface thermometer. This is the upgrade that took my smash burgers from good to great. The dials on Blackstone burners are imprecise. Knowing your griddle is actually at 425°F (not 350° because it’s cold outside) is the difference between a crust and a steam.
• A squeeze bottle with neutral oil (avocado or canola) for greasing the griddle.

Prep Before You Light the Burner

This is a fast-moving recipe once the griddle is on. Get everything ready first.

1. Form the patties. Divide the pound of beef into 8 equal 2-ounce balls. Don’t compress them. They should look like loose meatballs. Stack them on a plate and refrigerate until the griddle is hot.
2. Slice and prep the mushrooms. Wipe clean, slice ¼ inch thick. Mince the garlic. Strip the thyme leaves.
3. Mix the seasoning. Combine the kosher salt, pepper, garlic powder, and onion powder in a small bowl. I keep mine in a shaker bottle.
4. Prep the buns. Spread a thin layer of mayo on the cut sides of all four brioche buns. Set aside.
5. Have your cheese ready. Slices unwrapped and at room temperature. Cold cheese melts unevenly.
6. Stage your toppings. Lettuce washed and dried, onions sliced, sauces in squeeze bottles or small bowls.

You should be able to execute the cook in under 10 minutes once the griddle is hot. The prep is what gets you there.

Step-by-Step: How to Cook Blackstone Mushroom Swiss Smash Burgers

Step 1: Heat the Griddle to 425°F

Turn all your burners on high and let the griddle preheat for at least 8-10 minutes. Use your surface thermometer to confirm it’s reading between 400°F and 425°F across the cook zone. This is non-negotiable. A cool griddle is the #1 cause of smash burgers that stick and don’t crust.

Once it’s hot, hit the surface with a light coat of avocado oil from your squeeze bottle and spread it with a paper towel held by tongs.

Step 2: Start the Mushrooms

Move to the cooler side of the griddle (or turn one burner down to medium). Melt 2 tablespoons of butter, then add the sliced mushrooms in a single layer. Don’t crowd them — if they overlap, they’ll steam. Let them sit untouched for 2-3 minutes to brown on the first side before stirring.

Once they’re golden and have released their water, add the minced garlic and thyme. Toss for 30 seconds. Add the Worcestershire and let it reduce and glaze the mushrooms, another 30-45 seconds. Salt to taste. Push them to a holding zone on the cooler edge of the griddle and dot with the final tablespoon of butter — it’ll melt slowly and keep them glossy until assembly.

Step 3: Smash the Patties

This is the moment. Drop all 8 meatballs onto the hot zone of the griddle, spaced at least 3 inches apart. Place a parchment square over the first ball. Position your smasher on top, and press down hard and fast — you want the patty thinner than ¼ inch, ideally about 4 inches in diameter with ragged, lacy edges. Hold for 5 seconds. Lift the smasher straight up. The parchment will peel away clean. Repeat for the rest.

Immediately season the smashed tops with a generous pinch of your seasoning mix. Do not press them again. This is the single most important rule.

Step 4: The Flip

Let the patties cook undisturbed for 90 seconds to 2 minutes. You’re looking for the edges to turn deep brown and crispy, and for the top of the patty to start sweating juices and turning gray-brown around the perimeter. When you flip, use a thin, sharp-edged spatula and get under the crust. Slide the spatula in flat and scrape — the crust should release cleanly. If it tears, your griddle wasn’t hot enough or you flipped too early. Wait 15 more seconds and try again.

Step 5: Cheese, Stack, and Melt

Immediately after flipping, place a slice of American cheese on each patty (or every other patty if you’re doing doubles), followed by a slice of Swiss on top. For double-stack burgers, take an un-cheesed patty and place it on top of a cheesed one. The Swiss goes on top of the stack. Hit each burger with about a teaspoon of water on the griddle next to it and immediately cover with a basting dome or a metal mixing bowl. The trapped steam will melt the cheese in about 60 seconds.

Step 6: Toast the Buns

While the cheese melts, place the mayo-coated buns face-down on the griddle. They’ll go golden in 60-90 seconds. Pull them as soon as you see deep golden brown — they go from perfect to burnt fast.

Step 7: Build and Serve

Bottom bun. Optional smear of garlic aioli or Dijon. Patty stack with cheese. Heaping spoonful of garlic-butter mushrooms. Lettuce and onion if using. Top bun. Serve immediately.

The window between “perfect smash burger” and “smash burger that’s been sitting on the plate too long” is about 90 seconds. Have everyone at the table before the buns hit the griddle.

How to Tell When Smash Burgers Are Done

You can’t temp a 4mm-thick patty reliably. Trust the visual cues:

• The edges are dark brown and crispy
• The top of the patty has turned from pink to gray-brown
• Juices on top look clear or slightly pink, not red
• Total cook time was 2-2.5 minutes per side at 425°F

At this thickness, the patty hits 160°F internal almost instantly after flipping. There is no medium-rare smash burger. The whole point is the crust, and the crust requires fully cooked thin meat.

Common Problems and How to Fix Them

• The patties stuck and tore when I flipped them. Your griddle wasn’t hot enough, or you flipped too early. Get to a real 425°F before the meat hits the surface. And wait until the edges are clearly crispy and dark before you slide the spatula under.
• My mushrooms are watery and pale, not browned. You crowded them, or your griddle was too cool, or you stirred too soon. Mushrooms need single-layer real estate, high heat, and 2-3 minutes of undisturbed contact to brown. If you’re cooking for a crowd, do them in two batches.
• The cheese didn’t melt all the way. Use the steam dome trick — splash water on the griddle next to the patty and cover. Also: cold cheese melts poorly. Pull your slices from the fridge before you start cooking.
• My smash burgers turned out dry. You pressed them after the initial smash. You used 90/10 beef. You overcooked them — at this thickness, 3 minutes per side is too long. Or all three.
• The crust is good but not great. Hotter griddle, harder smash, less moving the patty during the first 90 seconds. The crust forms in the first cook. Don’t disturb it.

Customizations Worth Trying

• Make it a patty melt. Skip the bun. Use thick-sliced rye, butter the outside, build the burger between two slices and griddle the whole thing like a grilled cheese.
• Sub the mushrooms. Wild mushroom mix (shiitake, oyster, chanterelle) is incredible if you can splurge. Lion’s mane is unreal — meaty texture, faintly sweet.
• Add caramelized onions. Start them on the griddle before everything else. They take 25-30 minutes to truly caramelize, so plan ahead. Pile them under the mushrooms.
• Switch the cheese. Gruyere instead of Swiss is a luxury upgrade. Smoked gouda is fantastic. Provolone melts beautifully and plays well with mushrooms.
• Make a sauce. A quick aioli of ½ cup mayo, 1 minced garlic clove, 1 tsp lemon juice, ½ tsp Dijon, salt — game-changer.
• Try a brioche slider version. Use 1-ounce balls and Hawaiian roll slabs. Makes 12 sliders from this recipe. Perfect tailgating food.

What to Serve Alongside

The richness of a mushroom Swiss smash burger calls for something crispy and acidic on the side. My go-tos:

• Hand-cut fries (the Blackstone has space — toss them on while the burgers rest)
• Sweet potato fries from the air fryer
• A sharp vinegar-based slaw with red cabbage and apple
• Quick-pickled red onions
• Grilled corn elote-style
• Crispy tater tots
• A simple arugula salad with lemon vinaigrette

For drinks: a cold IPA, a crisp lager, an Old Fashioned, or a sharp ginger beer. The fat and umami in this burger wants something with backbone.

Make-Ahead and Storage

Patties: Form the meatballs up to 24 hours ahead, refrigerate covered. Mushrooms: Cook fully, cool, store in an airtight container for up to 3 days. Reheat in butter on the griddle for 60 seconds before serving. Leftover cooked burgers: Refrigerate up to 3 days. Reheat on the griddle at medium heat for 90 seconds per side. Never microwave a smash burger. The crust dies a sad death. Freezing raw patties: Smash into thin discs between parchment squares, stack, freeze flat for up to 2 months. Cook from frozen — add 30 seconds per side.

Frequently Asked Questions

What temperature should a Blackstone be for smash burgers? 400-425°F surface temperature. Use a surface thermometer to confirm. Below 400°F and you won’t get a true Maillard crust. Above 450°F and you risk burning before the patty cooks through.

How thin should I smash a smash burger? Thinner than you think — about ¼ inch or less. The patty should be 4-5 inches across after smashing from a 2-ounce ball. Lacy, ragged edges are the goal; they become the crispy bits everyone fights over.

Should I use 80/20 or 90/10 ground beef? 80/20 minimum for smash burgers. The fat renders out, fries the patty, and creates flavor. 90/10 produces a dry, hockey-puck result. If you can find 75/25 chuck, even better.

Why are my smash burgers sticking to the Blackstone? Three reasons, usually compounding: the griddle wasn’t hot enough (under 400°F), you didn’t oil it, or you tried to flip too early before the crust formed. Get to 425°F, oil the surface, and wait for visibly crispy edges before flipping.

Can I make these smash burgers without a Blackstone? Yes. A heavy cast iron skillet or carbon steel pan works beautifully — you just lose surface area, so cook in batches. The technique is identical: hot pan, hard smash, no pressing after, parchment between meat and smasher.

Should I season the beef before forming the patties or after smashing? After smashing. Salt drawn into the meat in advance changes the texture and pulls moisture. You want a loose, tender ball that smashes into a thin disc — and a seasoning crust that lives on the surface where it meets the heat.

Do I need parchment paper to smash burgers? You don’t strictly need it, but it makes life dramatically easier. Without parchment, raw beef sticks to the smasher and you tear the patty when you lift. A 4×4 inch square of parchment between the smasher and meat solves this entirely. Cheap and worth it.

Can I make the mushrooms ahead of time? Yes — up to 3 days in advance, refrigerated. Bring them back to life on the griddle in a tablespoon of butter for about a minute before serving. Don’t reheat them in the microwave; they’ll go rubbery.

What’s the best cheese for a mushroom Swiss burger? Real Swiss (Jarlsberg or Emmentaler) on top for flavor, American underneath for melt. If you’re picking just one, deli Swiss does the job — but the double-cheese move is worth the extra slice.

Why are my mushrooms watery instead of browned? You crowded them in the pan, the griddle was too cool, or you stirred too soon. Mushrooms need to be in a single layer, on a hot surface, and undisturbed for 2-3 minutes before stirring. Also: don’t wash them — wipe them clean.

How many smash burgers per person? A double-stack (two 2-ounce patties) is one generous adult portion with sides. For appetite-driven crowds, plan one double per adult plus a few singles to spare. For sliders, 2-3 per person.

Can I use frozen mushrooms? I wouldn’t. Frozen mushrooms release a ton of water and will steam rather than brown. Fresh creminis are inexpensive and worth the trip.

Is there a vegetarian version? Yes — sub the beef patties for thick-sliced portobello caps, smashed and seared the same way. Or use a plant-based ground (Beyond and Impossible both smash decently). The mushroom-Swiss-bun architecture works either way.

More Easy Blackstone Recipes

• BLACKSTONE GRIDDLE CINNAMON ROLLS
• BLACKSTONE GRIDDLE SAUSAGE & MUSHROOM FLATBREAD PIZZA
• BLACKSTONE GARLIC BUTTER LAMB CHOPS
• BLACKSTONE GRILLED CORN ON THE COB

Don’t Forget To Pin!

If you make this, I want to know how it turned out. Drop a comment, rate the recipe, or tag me on Instagram so I can see your crispy edges.

Now go fire up the griddle.