Velvety Mushroom Soup: The Best Use for Mushroom Stems

Even if you’re doing your best to cook root-to-leaf and nose-to-tail, there are probably still some edible bits you’re missing. Every other Sunday, we'll focus on one overlooked scrap, and show you how to turn what would otherwise be trash into a dish to treasure.

Today: Stem your waste of mushroom stems.

 
Foraging season is upon us, which means that our mycophagy (you’ll remember that’s the practice of consuming mushrooms) is in full swing—even if said foraging happens in the aisles of our local supermarket. But unless you’re dealing with mushroom varieties that are more stem than cap, like enoki or trumpet, there's one part of mushrooms we’re not always consuming: the stems.

Since shiitake mushroom stems can be tough and woody, these mushrooms are usually trimmed close to the cap. But that doesn't mean the stems need to go into the compost bin. If your shiitake mushrooms are very fresh, you can finely chop the stems and cook them. If they are older and the stems feel quite firm to the touch, then your best bet is to add them to a pot of stock or a batch of gravy give your dish more flavor.

Other types of mushrooms, like cremini and portobellos, can be trimmed very close to the base. Even though their stems don’t necessarily have to go to waste, a lot of recipes call for them to be removed regardless. It's time to stop discarding the stems rather than saving them for another use: Even if a recipe calls for the stems to be removed, you can just chop them up and use them along with the caps in dishes like pasta sauces, stuffing, noodle dishes, or vegetable paté. 
 

More: The real question is, to wash or not to wash mushrooms? Here's everything you need to know about prepping mushrooms.

Lastnightsdinner's Velvety Mushroom Soup is a great way to use up your mushroom stems, and its taste lives up to its name: It truly is velvety—without the use of any cream—and it's also intensely mushroomy, thanks to the trifecta of mushroom stock, dried mushrooms, and fresh mushrooms. The base doesn't start with a mirepoix, but you won't be missing out on any flavor: The mushrooms are deglazed with sweet vermouth, fresh thyme is used in both the stock and the soup, and a Parmesan rind (along with all of the mushrooms, of course) provides umami. Note that the recipe calls for more shiitake stems than caps. Plan to cook this soup after you make another recipe calling for shiitake mushroom caps, or simply use any extra shiitake caps in place of some of the cremini or white button mushrooms. 

Velvety Mushroom Soup by lastnightsdinner 

Makes one big pot

For the Parmesan-shiitake broth:

1 cup shiitake stems, cleaned
1 Parmesan rind, about 1-inch wide and 2 to 3 inches in length
1 leek top (the green leaves farthest from the white bottom), about 3 inches in length, rinsed well
2 to 3 sprigs fresh thyme
6 cups water
1 tablespoon kosher or sea salt

For the mushroom soup:

1 cup dried mixed wild mushrooms
1 cup boiling water
1 pound cremini or white button mushrooms (or use shiitake caps)
1 ounce wild mushrooms, such as shiitake, oyster, maitake, chanterelles, etc.
3 tablespoons unsalted butter
3 tablespoons extra-virgin olive oil
1 cup diced shallot or onion
Kosher or sea salt
1 tablespoon tomato paste
1/4 cup sweet red vermouth
6 cups Parmesan-shiitake broth or prepared vegetable or mushroom stock
1 tablespoon sherry vinegar
1 to 2 tablespoons fresh thyme leaves

See the full recipe (and save and print it) here. 

Know of a great recipe in the Food52 archives that uses scraps (anything from commonly discarded produce parts to stale bread to bones and more)? Tell me about it in the comments!

Photos by James Ransom