The Quick Take
To grill portobello mushrooms, gently wipe the caps clean and remove the stems. Brush them generously with a marinade of olive oil, balsamic vinegar, and minced garlic, letting them sit for 10 to 15 minutes. Place the mushrooms gill-side down on a medium-high grill (375°F to 400°F) and cook for 4 to 5 minutes. Flip the caps and grill for another 4 to 5 minutes until they are fully tender and have released their savory juices.Key Facts at a Glance
| Grill Fact | Target |
|---|---|
| Grill Temperature | Medium-High (375°F - 400°F) |
| Prep Time | 15 minutes (marinade) |
| Cook Time | 8 to 10 minutes total |
| Placement | Gill-side down first |
| Doneness | Deeply browned, tender, juices pooling |
Preparing the Perfect Portobello
Mushrooms are basically delicious little sponges. If you soak them in water to clean them, they will waterlog and steam on the grill instead of searing. Always clean portobellos by gently wiping the caps with a damp paper towel to remove any stray dirt.Once clean, pop out the stems. You can save these for a vegetable stock later. Some folks like to scrape out the dark black gills with a spoon, claiming they make the marinade muddy, but I leave them in. Those gills are flavor traps, holding onto every drop of oil, vinegar, and garlic you throw at them.Speaking of marinades, fat is your best friend here. Portobellos need a generous coat of oil to prevent sticking and to encourage a beautiful crust. I love using my Arteflame grill for these because the flat solid-steel cooktop lets the mushrooms sear in their own juices and marinade, rather than losing all that incredible flavor down through traditional open grill grates.Step-by-Step Instructions
- Clean the mushrooms by wiping the caps gently with a damp paper towel. Twist and pull the stems to remove them completely.
- Whisk together a quick marinade using 1/4 cup olive oil, 2 tablespoons balsamic vinegar, a minced garlic clove, and a pinch of black pepper.
- Brush the marinade generously over both sides of the mushroom caps, making sure it pools slightly in the gills. Let them rest at room temperature for 10 to 15 minutes.
- Prepare your grill for medium-high heat (about 400°F). If you are using an Arteflame grill, pour a little vegetable oil on three paper napkins, place them in the center, stack your firewood over them, and light the paper. After about 20 minutes, find a heat zone halfway between the blazing hot center grate and the cooler outer edge.
- Place the mushrooms gill-side down on the hot surface. Grill undisturbed for 4 to 5 minutes until a dark, caramelized crust forms on the edges.
- Flip the mushrooms using a sturdy spatula. Grill for another 4 to 5 minutes on the cap side until the mushrooms are completely tender and hot juices begin pooling in the center of the cap. Remove from the grill and serve immediately.
Pro Tip: Do not salt your portobellos too early in the marinating process. Salt draws out moisture, which can make the mushrooms rubbery before they even hit the fire. Add your finishing salt right as they come off the grill.
Common Mistakes to Avoid
- Washing them in the sink: Mushrooms absorb water instantly. A waterlogged mushroom will just steam and turn to mush. Always wipe them clean with a damp cloth instead.
- Skimping on the oil: Mushrooms need plenty of fat to sear properly. Don't be shy with a high-heat cooking oil like California Olive Ranch olive oil, or they will dry out and stick to the metal.
- Flipping them too often: Let the grill do its job. Constantly moving them prevents that glorious, savory crust from forming. Grab a good pair of OXO grilling tongs, flip them exactly once, and use the extra time to keep your in-laws away from the grill area.
- Cooking on a cold grill: If your cooking surface isn't hitting at least 375°F, the mushrooms will sweat instead of searing, leaving you with a sad, limp side dish.
Make It Your Own
Once you master the basic grilled portobello, it is incredibly easy to customize. These hearty caps are a blank canvas for all kinds of bold flavors and toppings.- The Portobello Burger: Top the grilled cap with a slice of Swiss cheese during the last minute of cooking, then serve on a toasted brioche bun with garlic aioli.
- Caprese Style: Fill the finished, grilled cap with fresh mozzarella, halved cherry tomatoes, and a drizzle of balsamic glaze, then garnish with fresh basil.
- Fajita Slice: Grill the caps whole, then slice them into thick strips and toss them with grilled peppers and onions for a killer vegetarian taco filling.
- Herb and Butter Finish: Drop a small pat of garlic herb butter into the gills right after flipping for an outrageously rich side dish.
Frequently Asked Questions
Should I remove the gills from portobello mushrooms before grilling?
You do not have to remove the gills, though it is a personal preference. Leaving the gills intact allows them to soak up your marinade for maximum flavor, but removing them with a spoon will give the mushroom a cleaner, lighter appearance and prevent dark juices from staining your bun.
How do you know when grilled portobello mushrooms are done?
Portobellos are done when they are significantly reduced in size, fully tender to the touch, and have deep brown caramelization on the outside. You will also see hot juices pooling in the center of the cap when they are ready to be pulled from the heat.
Can I grill sliced portobello mushrooms?
Yes, you can grill sliced portobellos, but they cook much faster—usually in just 2 to 3 minutes per side. A flat steel cooktop is ideal for this so the slices do not fall into the fire, but if you have standard open grates, you will need to use a grill basket.