Easy Grilled Portobello Mushroom Burger

Portobello mushrooms are a healthy meat substitute for the perfect grilled portobello mushroom burger recipe, filled with your favorite burger toppings, all tucked inside the cap. Cook dinner in under 20 minutes!

Even though I love my beet burger recipe, grilled portobello mushrooms make incredible burgers. In my opinion, portobello mushrooms make the best vegan meat replacement for various dishes. But my grilled portobello burger recipe makes the easiest and tastiest mushroom burger. And it's easy to make!

Jump to:

• How to Select the Best Portobello Mushrooms
• How to Store Portobello Mushrooms
• How to Prepare and Grill Portobello Mushrooms
• How to Remove the Gills From Mushrooms
• Marinade for Portobello Mushroom Burgers
• Marinade Burger Ingredient Substitutions
• How to Grill Portobello Mushroom Burgers
• Suggested Burger Toppings
• Additional Burger Topping Suggestions
• Recipe FAQs
• Tips
• What to Serve with Grilled Portobello Mushrooms?
• 📖 Recipe
• 💬 Reviews

How to Select the Best Portobello Mushrooms

• Avoid spots that indicate the beginning of rot when shopping for portabella mushrooms.
• Instead, look for caps that are firm and uniform in color. And look for dry mushrooms, not ones that appear wet or slimy.
• For example, I prefer lighter-colored mushrooms to darker ones for a more delicate flavor.
• On the other hand, if you prefer a deeper earthy taste, look for darker mushrooms, but be careful of spots and texture.
• Sometimes, a darker mushroom can appear dry, but it may be starting to get slimy, and no one likes slimy. 

How to Store Portobello Mushrooms

• Once you get the portobello mushrooms home, place them in the refrigerator in the packaging.
• But, if you selected the mushrooms yourself, without packaging, do not leave them in a plastic bag. Plastic bags, for instance, break down the mushrooms, causing them to smell and become slimy.
• Again, to avoid the slime, place the portobello mushrooms in a paper bag, such as a lunch bag, until ready to use. It is best always to store mushrooms in a paper bag to prolong freshness when you buy them without packaging.  
• Whatever you do, please cook portobello mushrooms before you freeze them. They can be stored in the freezer for up to one month. Then, when you wish to reheat the mushrooms, please make sure to thaw them entirely before reheating them. 

How to Prepare and Grill Portobello Mushrooms

• Although some experts suggest only clean mushrooms with a clean towel and no water, I beg to differ.
• Portobello mushrooms are delicate, so be careful as you remove the stem. Wash the outside of the mushroom cap using a small amount of water, gently washing away any dirt.
• Do not, for example, submerge the mushrooms to clean them. Instead, use the water to help remove the dirt, and carefully dry the mushrooms with a paper towel or cloth.

How to Remove the Gills From Mushrooms

• To remove the gills, turn the cap over to the open side and carefully remove the gills by scraping the gills with a small spoon.
• Then, use minimal water and a paper towel to pat dry.  
• Even though the gills are edible, they produce a yucky brown residue that makes a mess of your plate.

Marinade for Portobello Mushroom Burgers

• Balsamic Vinegar: Balsamic vinegar has a rich, complex sweetness that explodes in the mouth with notes of fig, molasses, cherry, chocolate, or prune. Traditional balsamic should pick up the flavors of the wood it matured in, and may have a slight smokiness. Traditional balsamic offers a mellow tartness rather than a strong acidity.
• Minced Garlic: I prefer using fresh garlic for the best flavor.
• Dijon Mustard: Dijon has a more intense, spicy flavor than yellow mustard. The sharp taste pairs well with vinaigrettes, sandwich spreads, vegan mayonnaise, or homemade sauces.
• Fresh Lemon Juice: The juice of the lemon is about 5% to 6% citric acid, which gives lemons a sour taste, yet its citrus flavor gives sauces freshness.

Marinade Burger Ingredient Substitutions

1. Mix 1 Tablespoon of red wine vinegar with 2 teaspoons of maple syrup to substitute balsamic vinegar. Adding sweetness to red wine vinegar gets close to the complexity and roundness of balsamic flavor.
2. Substitute fresh garlic cloves with dehydrated (or dried) minced garlic; use ½ teaspoon of garlic flakes in place of each clove. Granulated garlic: Use ¼ teaspoon of granulated garlic in place of each clove. Garlic powder: Use ⅛ teaspoon of garlic powder in place of each clove.
3. Stone ground mustard is an excellent substitute for dijon mustard.
4. Bottled lemon juice is a substitute for fresh lemon juice.

Generally, I suggest marinating overnight, but not this time. Because portobello mushrooms contain so much water, you only want to marinate for an hour or two at most. 

How to Grill Portobello Mushroom Burgers

1. Preheat the grill to medium or 400 degrees before placing the portobello mushrooms on the grill.
2. Begin grilling the portobello mushrooms with the opening up, so the marinade cooks inside the cup of the mushrooms. 
3. Grill the portobello mushrooms for 3 to 5 minutes on each side to allow them to gain color and grill marks. I love grill marks. 
4. Once you flip the mushroom, brush the mushroom caps with extra marinade to replace the moisture if the grill starts to dry them out.
5. You do not need any oil. The marinate, for example, will provide enough moisture without needing oil. 

Suggested Burger Toppings

One helpful tip when building the grilled portobello mushroom is to lay the opening side on the base bun. Not only does this help keep the bun dry, but it creates a bowl to stuff your toppings inside a crevice. For basic illustration, I used classic burger toppings:

• Sliced Onions: I like strongly flavored white or red onions. However, yellow onions are an excellent choice as well.
• Tomato Slices: I look for large tomatoes that are similarly sized to the portobello mushrooms so they slip right inside the opening.

• Dill Pickles: I chose dill pickle chips because they set nicely inside the crevice of the mushroom. Or, choose sweet or bread and butter pickles.
• Ketchup: Ketchup is a classic burger topping that brings a bright taste to the burger.
• Mustard: I prefer yellow mustard, but dijon, stone-ground, or horseradish mustard are other options.

• Romaine Lettuce: Then I top the portobello burger with Romaine lettuce and the toasted top of the bun.

Additional Burger Topping Suggestions

But, let's consider the other possibilities to fit inside a grilled portobello mushroom cap!

• Grilled Onions
• Raw or Grilled Jalapenos
• Pineapple (yep, it fits right in the mushroom hole)
• Vegan Cheese (of choice)
• Vegan Coney Chili Sauce
• Blackberry Dijon Sauce
• Guacamole
• Salsa
• Grilled or Raw Avocado
• Pickled Red Onions
• Pineapple Coleslaw
• Coconut Bacon
• Nacho Cheese Sauce
• BBQ Sauce

Whatever your toppings or fillings for the mushroom cap, everything stays inside and makes the perfect grilled portobello mushroom burger.  

Recipe FAQs

Tips

• Choose lighter, sturdy portobello mushrooms without any blemishes. 
• For a more earthy flavor, choose darker mushrooms, but still avoid blemish, indicating older mushrooms. 
• Remove the gills with the edge of a spoon to create a clean opening; discard the gills. 
• Wipe the debris from the mushrooms rather than use water to clean them. 
• Marinate the mushrooms with the opening up in a covered container so the center absorbs most of the marinade. 
• Grill the portobello mushrooms on a preheated grill, again opening side up for the maximum flavor from the marinade.
• Again, place the mushroom opening side up when serving the burgers, so the center of the mushroom holds the burger toppings in the open center. 

Heat the grill and make the best-grilled portobello mushroom burger recipe you've ever had!

What to Serve with Grilled Portobello Mushrooms?

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