How to Cook Portobello Mushrooms

In Praise of Portobellos
Botanical name: Agaricus bisporus

Portobello Mushrooms Nutrition Facts

Along with its smaller crimini and white button cousins (which share the scientific name), this “meaty” mushroom variety is gaining worldwide popularity as a “superfood” not only because it’s nutritionally dense, but delicious. Mushroom lovers enjoy them in stir fries, casseroles, soups, omelets, and salads, but one hearty preparation style is to give them solo status on a bun as a meatless, gluten-free burger with all your favorite condiments like lettuce, pickles, and tomatoes.

Easily the largest, the Portobello can measure six inches across the top. If you look at the underside of this mushroom type, you’ll see distinctive webs under the cap, called gills. The literal translation of “agaricus” is “gilled mushroom,” which in some scientific circles replaces an older name, “Agaricus brunnescen,” which denotes this species’ tendency to brown when bruised. “Portobello” is the market-motivated moniker given to the large-sized Agaricus bisporus, sometimes described as an oversized crimini, which is sometimes sold as a “Baby Bella.”

About 90 percent of the mushroom production worldwide is in the US, most of it grown in Pennsylvania. That’s 900 million pounds a year, which fetches about $800 million annually.

Chlorophyll, the green pigment in plants, isn’t present in this “’shroom,” so sunlight isn’t necessary for them to proliferate. Because they absorb and concentrate whatever medium they’re planted in, good or bad, it’s important for the mushrooms you eat to be grown organically. Like many others, Portobellos thrive in a “secondary decomposition” atmosphere that requires the breakdown of fungi and bacteria. According to

“All mushrooms grow from microscopic spores, not seeds. Plants growing from spores are called fungi. A mature mushroom will drop as many as 16 billion spores. Spores must be collected in the nearly sterile environment of a laboratory and then used to inoculate grains or seeds to produce a product called spawn (the mushroom farmer’s equivalent of seed).”

In a controlled environment, organic material makes a nutritionally balanced substrate. When mushroom spawn is mixed in, usually purchased from a commercial lab, the blend is transferred to beds and spread with “casing” made from peat moss to hold in moisture. In a 16- to 35-day cycle, the mushroom “pins” that emerge are hand-harvested.

Whether purchased or harvested yourself, keep mushrooms fresh by placing them in a paper bag in the refrigerator. Avoid airtight containers, which can collect moisture and cause spoilage. As for preparation, one of the best methods is to sauté them between six to eight minutes, depending on their size and density. Avoid overcooking to release the best flavor and most beneficial nutrients.

Health Benefits of Portobello Mushrooms

Of the 140,000 fungi known to produce mushrooms, only about 100 of them are being investigated for possible health-promoting benefits. While they’ve produced some of the most powerful natural medicines in the world, only half a dozen contain compounds that can boost your immune system, and some of those are significant. Penicillin, streptomycin, and tetracycline, for instance, all come from fungal extracts.

Low in saturated fat and cholesterol and high in fiber, Portobellos are an excellent source of copper, which your body needs to produce red blood cells and carry oxygen through your body. They also offer three important B-complex vitamins: riboflavin for maintaining healthy red blood cells; niacin for supple skin and properly functioning digestive and nervous systems; and pantothenic acid, which aids in the release of energy from the fat, protein, and carbohydrates in the food you eat.

Just one cup of mushrooms has the potential to release at least 15 different vitamins, minerals, and phytonutrients. A single Portobello contains more potassium than a banana – 630 mg per serving – which helps maintain normal heart rhythm and muscle and nerve function, as well as a balance between your fluid and minerals. This in turn helps control blood pressure.

It’s established that mushrooms are a fungi, but they’re sometimes placed in the vegetable category even though they have a protein profile similar to meat, beans, or grains. Interestingly, serious discussion is underway regarding how mushrooms will be categorized in the future. According to an article in Nutrition Today:1

“…Mushrooms’ nutrient and culinary characteristics suggest it may be time to reevaluate food groupings and health benefits in the context of 3 separate food kingdoms: plants/botany, animals/zoology, and fungi/mycology.

“Initially, mycology, the study of fungi, arose as a branch of botany because fungi were considered primitive plants. Fungi now are accepted as a separate kingdom based on cellular organization rather than on observable and other features. Major differences that distinguish fungi from both plants and animals include the following:

    Plants have chlorophyll and make their own food through photosynthesis.

    Animals ingest their food.

    Fungi, lacking chlorophyll, exist on decaying material in nature and on substrate of various compositions when commercially grown.”

Among all natural food sources, mushrooms are the only one containing selenium, a compound necessary for the proper function of the thyroid and male reproductive systems. It’s an antioxidant that protects the cells from damage from heart disease, certain cancers, and age-related diseases.

Portobello Mushrooms Nutrition Facts

Serving Size: 3.5 ounces (100 grams), raw
  Amt. Per
% Daily
Calories 26  
Calories from Fat 2  
Total Fat 0 g 0%
Saturated Fat 0 g 1%
Trans Fat    
Cholesterol 0 mg 0%
Sodium 6 mg 0%
Total Carbohydrates 5 g 2%
Dietary Fiber 1 g 6%
Sugar 2 g  
Protein 3 g  
Vitamin A 0% Vitamin C 0%
Calcium 1% Iron 3%

*Percent Daily Values are based on a 2,000 calorie diet. Your daily values may be higher or lower depending on your calorie

Studies Done on Portobello Mushrooms

In one study,2 researchers extracted the compound 2-amino-3H-phenoxazin-3-one from the edible brown mushroom, Agaricus bisporus, and found evidence suggesting that it contains anti-inflammatory properties that may be useful in the treatment of autoimmune diseases as well as for bacteria-induced chronic-inflammatory diseases.

Crimini mushrooms along with other mushroom species of mushrooms were found to “interfere” with the processes causing atherogenesis and cardiovascular disease in another study.3 Scientists concluded that diets that involve dietary fungi – mushrooms – as well as fruits and vegetables minimize CVD risk. Additionally, “common, readily available, and affordable mushrooms such as white button, or Agaricus bisporus, as well as specialty mushrooms including shiitake appear particularly beneficial to health.”

One way to discover the ways a specific food can be nutritionally beneficial is to look at the compounds it contains. In mushrooms, a rather obscure vital compound is the amino acid ergothioneine, which the journal Nature4 revealed is not only obtained exclusively through the diet, but fairly exclusive to mushrooms. It’s described as "an unusual sulfur-containing derivative of the amino acid, histidine," which scientists suggest has a specific role in protecting your DNA from oxidative damage.

How to Cook Portobello Mushrooms

Portobello mushrooms can be sautéed and served as a side dish, added to meat dishes or salads, used in soup stock, or even stuffed before being roasted or grilled. Whichever way you want to use or cook Portobello mushrooms, you must start by cleaning them properly. Here is an easy method:

  1. Remove the stem. Hold the cap in one hand and the stem in the other and give it a firm twist – it will come right off.
  2. Scrape off the black gills on the underside of the mushroom cap using a spoon. Carefully pry them with the tip of the spoon so they detach in neat, discrete chunks and do not stain the whole cap and your hands. Although these gills are edible, they can turn your food an unappetizing brown color.
  3. Use a damp cloth to clean the mushroom caps.

Optional: for the cap to lay flatter and give you more uniformed slices, remove the outer edges that attach it to the gills.

You can now use the Portobello mushroom for your recipes. As for the stems, you can opt to discard them, but since they are edible (and if you don’t want them to go to waste), you can use them to make delicious stock instead.

There are numerous ways to cook Portobello mushrooms, but one of the easiest methods is by frying or sautéing. Before frying, coat the mushrooms with rich seasonings such as ground cumin, red peppers, cardamom pods, ground cinnamon, ginger or garlic.

It usually takes only eight minutes or less to cook Portobello mushrooms to give them a tender consistency. Stir them frequently to prevent them from burning. Make sure to also use coconut oil for frying, as this is the only oil stable enough to withstand high temperatures.

Grilling or roasting is another easy way to cook Portobello mushrooms, wherein you don’t need to remove the gills. Try the recipe below.

Healthy Portobello Mushroom Recipe:
Grilled Portobello Mushroom Burgers

Portobello Mushroom Healthy Recipes


4 large Portobello mushroom caps


1/3 cup balsamic vinegar

½ cup water

2 tsp. honey

1 garlic clove, minced

¼ tsp. cayenne pepper (optional)

2 Tbsp. olive oil


  1. Clean mushrooms with a damp cloth and remove the stems. Place in a glass dish, stem (gill) side up.
  2. In a small bowl, whisk together the vinegar, water, honey, garlic, cayenne pepper, and olive oil and drizzle it over the mushrooms. Cover and marinate in the refrigerator for about 1 hour, turning the mushrooms once.
  3. Prepare a charcoal grill, gas grill, or broiler to medium heat. Away from the heat source, lightly coat the grill rack or broiler pan with cooking spray. Position the cooking rack 4 to 6 inches from the heat source.
  4. Grill or broil the mushrooms until tender – about 5 minutes on each side, turning often. Baste with the marinade to keep them from drying out. Using tongs, transfer the mushrooms to a plate.
  5. Serve on buns and garnish with your favorite burger options, such as tomatoes, pickles, onions, ketchup, and lettuce. Enjoy!

(From Mayo Clinic’s Healthy Living Recipes)

Portobello Mushroom Fun Facts

Because mushrooms don’t require sunlight to flourish, the French were able to utilize caves as production sites for some of the first commercial mushroom operations in the mid- to late-1600s, during the reign of King Louis XIV.


Sometimes referred to as a large version of the crimini mushroom, Portobellos are in the top three favorites among all varieties. Like other mushrooms, they’re a type of fungi grown from microscopic spores, not seeds. Around half a dozen mushrooms contain immune boosting compounds, which include penicillin, streptomycin, and tetracycline. Portobellos are an excellent source of copper, as well as riboflavin, niacin and pantothenic acid. Just one contains more potassium than a banana. Research shows Agaricus bisporus contains the amino acid histidine, which may protect your DNA, as well as antioxidants to fight inflammation and cardiovascular disease.