How to Cook Cremini Mushrooms: Fixing the Gray, Watery Pan

White button, cremini and portobello are one species, Agaricus bisporus. The white button comes from a white strain, cremini from a brown strain sold with the cap still closed, and portobello from the brown strain left to open. Chitin rises as the mushroom matures, so an open portobello chews more firmly than a closed cap.

Gray, watery mushrooms come from a crowded pan, a cool pan or both. The fix is an empty pan heated first, a single layer with gaps, fat only after the water has gone, and salt after browning. Leave the lid off, because it traps the steam.

In a comparison of four cooking methods, grilling and microwaving best kept the nutritional profile and deep frying caused the most severe losses, although a microwave does not brown anything. Cremini stems are firm and edible, so you only need to trim a dry or dirty base.

Cremini brown well when the water they release has a way out of the pan. That means a hot, empty pan, one layer of slices with gaps between them, fat once the water has cooked off and salt once the pieces have browned. Get the heat and the space right and the gray, watery pan stops happening.

It also pays to know what you are holding. White button, cremini and portobello are one species, sold in two color strains and at different ages. The age tells you how firm a slice will stay in the pan and which dishes it suits.

Why Do Cremini Go Gray and Watery?

Almost every complaint about cooked mushrooms comes back to one cause, and it has nothing to do with the mushrooms. Mushrooms are mostly water. Heat them and that water leaves the cells, and the pan either boils it off or fills up with it.

Two things put you in the right-hand column, and they are the same two every time. Crowd the pan and the water from the first pieces is still sitting there when the last ones start to release theirs. Start with a pan that is too cool and it never gets ahead of the water at all.

Neither of those comes from the mushrooms, the brand, the season or the strain. It is a heat-and-space problem, and each fix on this list gives the water somewhere to go.

• A pan that was hot before anything went into it
• Fewer pieces in it than feels efficient
• No lid, because a lid keeps the water in the pan
• Patience for a second batch, which takes less time than rescuing a wet one

The Dry-Pan Method

When you sauté mushrooms, the order of the steps does more work than any one step. Each line below depends on the one above it. The third line goes against the usual advice to heat the oil before anything else goes in.

Fat waits because of where the water goes. Oil poured in at the start sits in the pan while the mushrooms flood it, and you end up with oil floating in mushroom liquid. That mix browns nothing and coats everything. Wait until the pan goes dry again and the pieces start to squeak and color, and then butter or oil meets hot, dry surfaces and browns them.

Salt waits for a similar reason. It draws water out of the mushroom by osmosis, so salting at the start works against the very thing you want. Covering the pan would undo the whole method too, because a lid traps the steam you are trying to lose.

Four Cooking Methods Compared

The pan is not your only option, and researchers have measured the others against it. A 2017 study of cooking methods boiled, microwaved, grilled and deep fried four cultivated species, with this one among them. Here is what each method did.

The microwave result surprises people, but the reasoning is simple. Microwaving heats the water inside the mushroom directly and quickly, with no added fat and no long exposure. On the measures that study used, that worked in the mushroom's favor. It still will not taste like a seared mushroom, because browning is a flavor process and a microwave does not brown, so you give that flavor up.

Boiling brings its own trade, and it is the most interesting of the four. It raised the beta-glucan fraction and lowered antioxidant activity at the same time. So boiling is neither simply good nor simply bad, which is how most cooking choices work out.

How Do You Clean Cremini and Their Stems?

Wipe cremini if they look clean and rinse them if they are gritty. Most of the argument about washing mushrooms is overblown here. Rinsing them under the tap for a few seconds will not turn them into sponges, because the cap surface does not soak up much water.

What water does do is sit on the surface, and the pan has to spend its first minutes driving that water off. So dry rinsed cremini properly on a cloth before they go anywhere near heat. Washing them causes no harm, and cooking them wet does.

Cremini stems are firm, clean-tasting and completely edible. They lack the woody texture that some other species carry in their stems, so cutting them off throws away good food. Trim the very base if it is dry or dirty, and slice the rest along with the cap.

• The stem is denser than the cap, so cut both to a similar thickness and keep both
• A torn veil means an older mushroom, and an older mushroom is not a damaged one
• Gritty mushrooms are worth rinsing, and wet mushrooms are worth drying properly first
• Dark patches on the cap come with age and do not mean spoilage, though slimy ones are past it

The veil is the last small detail. If the thin skin under the cap has started to tear and you can see the gills, the mushroom is simply a little older and closer to a portobello. Expect darker color and stronger flavor once it hits the pan.

Are Cremini the Same as Button Mushrooms?

They are the same species. The three names on the shelf describe strain and age, and the research literature treats all three as Agaricus bisporus.

Lined up together, the link between them is obvious. In three separate punnets on a shelf it is easy to miss, so few shoppers know it. The color comes from the strain, since the species has both brown and white strains. Age is a separate thing that happens to arrive on the same shelf.

Age is the part you feel at the stove, because an open portobello carries more structural chitin than a closed cap. So when you swap one punnet for another as a cremini substitute, you are choosing a strain and a maturity. It is closer to picking between a green banana and a spotted one than between two vegetables.

Chitin and the Older Cap

You can measure how the mushroom changes with age, and one number carries most of the story. A 2005 study of mushroom composition found that chitin rose as the mushroom matured. Portabella had the most chitin of the varieties measured, at 8.0 percent.

Cooking changes the makeup of the mushroom as well. In the same study, cooking lowered chitin and raised starch, total dietary fiber and fat. So the heat softens the very firmness you are managing at the stove, and an overcooked mushroom slumps. Crude protein came out highest in crimini among the varieties measured, which is a small point in favor of the middle age.

Where Cremini Beat Button and Portobello

Picking the middle age has real effects in the pan. It suits some jobs and works against others.

Braises show the gap most clearly. White buttons in a long-cooked sauce tend to give up and go soft, and the extra structure in cremini keeps a piece you can still find on the fork. That same structure works against you in a duxelles or a soup base, where you want the mushroom to disappear and the youngest form does the job better.

• Choose white button when you want the mushroom to melt into something
• Choose cremini when you want to still find it on the fork
• Choose portobello when the mushroom is the center of the plate
• All three take the same method, and only the timing shifts

If you have more than you can use in a few days, leaving them in the fridge and hoping will not work. They keep maturing in there, and drying them makes better use of a surplus than watching them open. Once you want a specific dish, mushroom soup with browned cremini starts by browning them.