How to Cook Paddy Straw Mushrooms: The Can Is Already Cooked

Canned straw mushrooms are already cooked, so drain them, rinse the brine off, blanch them for thirty seconds if they still taste tinny, and give them one to two minutes of heat at the end of the dish. Fresh ones need three to five minutes, a same-day deadline and room temperature rather than a refrigerator.

Almost everyone cooking straw mushrooms outside the tropics is cooking a can, and the can changes the entire job.

What is inside was cooked when the tin was sealed. Avoid unnecessary extra cooking of canned mushrooms and drain their brine before use.

If yours are fresh from a warm-country market, the two sections that matter most are the one on cold and the one on cleaning, because that is where fresh ones are usually lost.

Canned or fresh decides everything

One species, Volvariella volvacea, reaches kitchens in two states. They have almost nothing in common at the stove.

The canned ones are already cooked, which is the single fact that most recipes leave out and the reason so many bowls end up with rubber in them.

Fresh ones are a tropical crop, grown on rice straw and cotton waste in countries warm enough to keep a bed above thirty degrees, and our guide to growing paddy straw mushrooms covers what that takes.

They are harvested as firm closed eggs, which is a stage almost no other cultivated mushroom is sold at, and our record for the paddy straw mushroom has the species detail.

The name causes its own small confusion in shops. Straw mushroom, paddy straw mushroom and Chinese mushroom all mean this species, and a can may carry any of the three.

They turn up dried occasionally in specialist shops, wanting twenty minutes in hot water first and coming back with more flavor than the canned version but never with the snap.

If a shop near you stocks neither form, our page on a paddy straw mushroom substitute covers what comes closest, though nothing reproduces the texture exactly.

The reason the West sees tins and not baskets is not import law or demand. It is that this mushroom collapses in transit at the temperatures used to ship every other vegetable.

Peeled or unpeeled on the label

Two words appear on straw mushroom cans. No tin has ever explained either of them, and the shelf label rarely helps.

Unpeeled means the whole egg, still wrapped in the outer sack the mushroom grew inside. They are smooth ovals, they hold their shape in liquid, and they are the ones you have seen bobbing in a coconut soup.

Peeled means that sack has been taken off, which uncovers a small cap on a short stem and makes the thing look like a mushroom rather than an egg.

Which one to buy comes down to three things:

• Unpeeled for anything wet, because the sack holds the shape in a broth.
• Peeled for anything sauced, because there is more surface and no skin over it.
• Either one halved, when you want a cut face in a soup and a shape on the spoon.

Neither is better than the other and neither costs more, which is why no can bothers to argue for one.

There is a size grading underneath the two words that matters more than either. Small ones stay firm and large ones have more space inside, so a can of large unpeeled mushrooms goes soft sooner in a broth than a can of small ones.

If a shop only stocks one kind, buy it. The difference decides how they look on the spoon rather than whether the dish works.

Getting the can taste out

The tinny taste that people blame on the mushroom is not the mushroom.

1. Open and drain

   Tip the whole tin into a colander and let the brine run off completely.

2. Rinse under cold water

   Half a minute of running water, moving them with your fingers, is enough for most cans.

3. Blanch for thirty seconds

   Boiling water, then straight back into the colander, for cans that still smell of the brine.

4. Dry them properly

   A tea towel or a spin in a salad spinner, because wet ones will not brown.

Only the third step is optional, and it is the one worth adding when a can has been on the shelf a long time.

That brine is salt and citric acid and it soaks into the outside of every mushroom over months on a shelf. Rinsing takes out the bulk of it in about thirty seconds.

The blanch is the step people skip and the one that finishes the job. It costs half a minute and removes the last of the metallic edge that a rinse leaves behind, and it does not cook them further in any way that matters.

Drying afterwards is not optional if the mushrooms are going into a dry pan, and a salad spinner does it faster than any amount of patting.

One number on the can is worth reading before you buy several. Net weight includes the brine, and the drained weight is usually a little over half of it, so a large-looking tin holds less than it appears to.

What the rinse cannot do is put anything back. Canning costs the mushroom some of its firmness and most of its aroma, which is why a fresh one tastes noticeably cleaner even after identical cooking.

How much heat they actually need

Two numbers cover almost every dish here. Which one applies depends entirely on whether the mushrooms came out of a tin.

1. Get the pan properly hot

   Wide and dry, over the highest heat the burner gives, before anything goes in.

2. Aromatics first

   Garlic, ginger or chili, thirty seconds, so the oil carries flavor before the mushrooms arrive.

3. Mushrooms in, drained and dry

   One layer, tossed rather than stirred, so they meet the metal.

4. One to two minutes for canned

   Long enough to heat through and pick up color, and no longer.

5. Three to five for fresh

   They shrink slightly and turn from matte to glossy when they are done.

6. Sauce at the end

   Oyster sauce or soy off the heat, because liquid ends the browning.

The fourth and fifth steps are the whole difference between the two products, and everything around them is identical.

A canned straw mushroom that has been in the pan for five minutes has gone from firm to squeaky to rubbery, and there is no way back from the third stage.

Fresh ones behave more like an ordinary mushroom, but they still finish faster than a button, because the flesh is thin over a hollow interior.

Overcooking has a visible signature in both cases. They shrink, wrinkle, and let go of a thin gray liquid that dulls whatever sauce they are sitting in.

Wet mushrooms in hot oil are the other thing to plan for. A drained tin still holds water in the hollow middle, and tipping it straight into a wok produces a burst of spitting that a minute in a colander would have avoided.

Halved ones behave better than whole ones in a dry pan. A cut face sits flat on the metal and browns, where a whole egg rolls and only ever touches at one point.

In a mixed stir-fry they go in near the end rather than at the start, after the harder vegetables have had their time and before the sauce goes down.

When to add them to a soup or a hot pot

More straw mushrooms end up in soup than in a wok. A pot poses a different timing problem from a pan, because the pot is already hot when they arrive.

Only the third row is about attention rather than a clock, because a hot pot never finishes.

The rule underneath all four rows is that the mushroom is never the thing the pot is waiting for. Everything else finishes, and then they go in.

Three things go wrong when they go in early:

• They shrink to about two thirds and stop looking like the thing on the menu photograph.
• They give up liquid that turns a clear broth cloudy.
• They soften all the way through and lose the snap that was the reason for adding them.

A hot pot is the one case that needs managing rather than timing, because the pot stays on. Adding a handful at a time keeps the last ones as good as the first, and tipping a whole tin in at once guarantees the opposite.

The hot pot failure has a name in most households that eat them. Someone finds the last four at the bottom of the pot half an hour later, and by then they have the texture of a pencil eraser.

Cleaning fresh ones

This is the one mushroom on this site where a quick rinse is not a mistake.

They grow in straw and compost, they are picked by hand out of a warm bed, and they arrive with bits of both stuck to the outside.

1. Brush off the loose material

   Most of the straw comes away dry with a thumb or a soft brush.

2. Rinse briefly under the tap

   Cold water, a few seconds each, working into the folds where grit collects.

3. Halve any that are larger than a walnut

   Lengthwise, through the cap and stem inside, which also lets you see the flesh.

4. Dry and cook the same day

   A towel, then straight to the pan, because they do not improve on the counter.

The reason water is allowed here and forbidden elsewhere on this site is the destination. Straw mushrooms mostly end up in wet dishes, so a surface that carries a little moisture costs nothing.

Grit hides in the folds of the outer sack rather than under gills, because at the egg stage the gills are still sealed inside.

Some of what a market sells will have opened already. The sack splits, a small gray cap pushes out on a short stem, and what you have is a normal-looking mushroom rather than an egg.

Opened ones are perfectly good and often cheaper, but they cook faster and go soft sooner, so they belong in a stir-fry rather than a slow pot.

Halving them is worth doing even when they are small enough to leave whole. A firm white interior is a good mushroom, and a brown mushy one is a mushroom that spent a night somewhere cold.

Never put fresh ones in the fridge

Every instinct says the fridge. That is the one place fresh straw mushrooms genuinely cannot go.

Research on postharvest handling documents tissue breakdown at ordinary refrigerator temperature rather than the slow ageing that cold produces in a button mushroom.

One preservation study compared holding them at fifteen degrees against four and found the warmer temperature kept them longer, which reverses everything a home cook has been taught about vegetables.

The practical version is short. Keep them at room temperature, in a paper bag or an open basket, and cook them today.

This is also why the markets that sell them fresh keep them in open baskets on a counter, which looks careless to anyone raised on chilled produce aisles and is the correct handling for the species.

If today is genuinely impossible, cook them now and refrigerate the cooked dish, which keeps perfectly well. Our page on storing paddy straw mushrooms goes through the options in more detail.

Do you have to cook them

Yes. Unusually for this question, the answer here is specific to the species rather than a general caution about mushrooms.

Fresh straw mushrooms are not eaten raw in any cuisine that uses them, and they carry a protein that heat breaks down and a raw mushroom does not.

Two minutes of real heat is the working minimum for fresh ones, and any of the methods on this page comfortably clears it.

The canned exception is worth stating plainly because it comes up constantly. Cold, rinsed, canned straw mushrooms are a normal salad ingredient across Southeast Asia and there is nothing to worry about in that.

Canning does the job thoroughly rather than partially. The tins are heated well past boiling under pressure, which is more heat than any pan at home will apply.

Our page on eating mushrooms raw covers where the line sits for the rest of the species on this site, most of which are less clear-cut than this one.

The egg that has killed people

Buying a labeled cultivated product and collecting a wild specimen require different identification decisions.

A straw mushroom is sold as a closed white or gray egg sitting in a sack at the base. A young death cap is also a closed egg sitting in a sack at the base, and so is a young destroying angel.

That resemblance is not a curiosity. It is one of the best documented patterns in mushroom poisoning, and it repeats wherever people who grew up eating straw mushrooms meet Amanitas that do not grow at home.

Two of those four rows are useless on a closed egg, which is exactly the problem. The ring and the gills only declare themselves once the mushroom has opened, and the egg is the stage a straw mushroom is picked at.

The page on mushrooms with a volva gathers the species that share the sack, and it is worth reading before any of them go in a basket.

There is a second trap inside the first one. Familiarity with the shape is what makes the mistake possible, so the people most at risk are the ones who have handled real straw mushrooms for years in a country where no deadly Amanita grows.

Buy them from a reliable source. Treat an unidentified wild egg-shaped mushroom in a sac as potentially dangerous until a competent identification establishes what it is.

What they taste like

Nobody buys a straw mushroom for its flavor. That is a description rather than a complaint.

Readers eating them often will find the numbers on our paddy straw mushroom nutrition page, which is a more useful place for them than a paragraph here.

The texture is the reason they have a permanent place in Southeast Asian cooking. The outside is smooth and a little slippery, the inside gives way with a small snap, and nothing else in the aisle does both at once.

Our roundup of the best mushrooms for stir-fry sets them against the mushrooms that bring more flavor to the same hot pan.

That combination has a short list of homes. These four cover almost everything they are used for:

• Coconut and lemongrass soups, where the texture stands out against a soft broth.
• Clear broths and noodle bowls, where nothing else provides a snap.
• Hot pots, where they are added and eaten in the same minute.
• Fast brown stir-fries with oyster sauce and something green.

Where they do not belong is a dish built on mushroom flavor alone, since a cream sauce or a mushroom soup asks for something they simply do not have.

Quantity is easy to misjudge because they shrink less than most mushrooms. A drained tin serves two people generously as part of a mixed dish, which is more than the same weight of button mushrooms would.

Used for what they do rather than what they are not, they are one of the easiest things in the aisle to get right. A tin, a colander, a hot pan and about ninety seconds is the whole of it, which is not a sentence that can be written about many mushrooms.