Simple ways to turn kitchen scraps into delicious soups

Onion and garlic skins and ends

Corn cobs

Parmesan rinds and other hard cheese nubbins

Green herb stems

Carrot and other vegetable peels, stalks and stems

Wilted (but not slimy) greens, such as spinach and kale

Poultry carcasses and meat or poultry bones

Shrimp/crab/lobster shells and fish bones, heads and tails

Mushroom stems and trimmings

Stale bread

A few best practices

Strong vegetables

Certain vegetables are very flavorful, so can overpower a soup if used in excess. Cruciferous vegetables like broccoli, cauliflower, cabbage and Brussels sprouts will give your soup a strong broccoli flavor, and can become bitter if cooked too long, so use them in moderation unless that’s the flavor you’re going for. Similarly, a whole heap of alliums — onions, garlic, leeks, etc. — will yield a strong oniony flavor: Great if you’re making an onion soup, less great if you want more subtle flavors to shine. Celery, too, can pack a wallop if you use too much, so unless you’re making a celery soup, you may want to exercise restraint.

Poultry carcasses, meat bones and seafood/fish shells and bones

Save up the pieces and parts you might not eat otherwise — skin, bones, shells, even small bits of meat — and you can use them to impart flavor and body to broths and, in turn, other soups. (More on this below.)

Don’t forget about cheese bones and mushroom bits!

Rinds of Parmesan and other hard, aged cheeses can impart umami and depth to scrap soups — especially helpful for plant-based broths. Simmer cheese rinds in the soup (even a little piece can do a lot of work) and remove them before serving. Mushroom stems also impart savory goodness; simmer and strain them out unless pureeing the soup.

Bulk it up with stale bread or leftover grains

Hold onto leftover bread crusts, cooked grains or pasta. Stale bread has long been used to thicken soups (think of two Italian classics, pappa al pomodoro and veggie-dense ribollita). Leftover cooked grains like farro, barley, and rice, or couscous or pasta, can also stretch the soup to make it more toothsome and feed a bigger crowd. Add these at the end so they retain their shape and don’t get mushy.

How to build a solid base

Soup begins, first and foremost, with a liquid. While you can use a combo of water, salt and other seasonings as the foundation for many soups, beginning with an already robust broth gives your soup a head start.

Vegetable scrap broth

Combine your collected scraps in a large, heavy pot such as a Dutch oven. Add some salt, pepper, herbs and spices and top with water to cover. Bring to a boil, then lower the heat to a simmer, cover, and cook until the liquid has taken on sufficient color and the vegetables and herbs have released their flavor, 1 to 3 hours. From here, you can strain the broth through a fine-mesh sieve to remove the solids, or if using as a base for a pureed soup (see below), just fish out the large, inedible chunks (like onion skins and bay leaves) before blending. Use the strained broth in soups (or to cook a big pot of beans!). Broth will keep in the fridge for three to four days or in the freezer for up to a month.

Poultry or beef broth

There are nearly infinite ways to make a basic bone broth. We like Sherri Brooks Vinton’s versatile method, or you can use the following template as your guide: Combine your  bones (and in the case of poultry, also skin and carcass) — and whatever vegetable scraps you might have collected (onion, garlic, carrot and celery are good complements — some people like to roast the veg first at 400F to intensify their flavors). Place these in a large, heavy pot like a Dutch oven, add water to cover, and bring to a boil. Then reduce the heat and simmer, covered but vented, for 8 to 12 hours, replenishing the water as needed, until a rich, hearty stock forms. Strain out the solids as directed above (depending on the final use for the broth, you may want to do this several times) and compost them. Store the resulting liquid gold in your fridge for a few days or freeze it for longer storage.

Note: If you have only small amounts of chicken and/or beef bones, you can combine them in a single stock; just be sure to reserve gamey bones (like lamb or venison) for their own stock because they can overpower other flavors.

Seafood or fish broth

For a simple seafood stock, the process is essentially the same: Combining a collection of crustacean shell scraps, like lobster, crab and shrimp, with aromatic vegetables, adding water to cover by about an inch, and simmering (but not boiling!) until the ingredients yield their fragrance and body. Hank Shaw at Hunter, Angler, Gardener, Cook recommends adding tomato paste to seafood stock, and uses a genius technique for straining out the solids: He freezes the liquid and then lets it defrost over a coffee filter to strain out any fat or shell-y bits. Shaw also has an easy recipe for fish stock that you can make with reserved heads, tails and bones (just be sure to remove any gills, which will spoil the broth).

Parm-bone broth

This cheesy, umami-forward broth is a great base for hearty, savory soups like minestrone, Italian wedding soup and pasta in brodo. Justine Doiron (@justinesnacks) has an excellent recipe that’s worth trying if you have a couple of generous Parm rinds stashed away.

Different scraps, different uses

From here, you can use one of the above broths as a foundation, or just start from scratch with scraps and enough liquid to cover (don’t hesitate to use packaged broth if that’s what you’ve got — this is a no-judgment zone). Here are some ideas for what to make from the broths/stocks and scraps you’ve got on hand.

Corn cobs or root vegetable scraps (such as potato and parsnip): potage, creamy corn chowder or corn and potato soup, scalloped potato soup

Onion scraps: vegetarian French onion soup, vichyssoise, onion stock

Mushroom stems: basic veg or beef stock, mushroom barley soup, Food 52’s Velvety Mushroom Soup

Poultry scraps: poultry bone broth/stock, avgolemono, classic chicken noodle soup, Chinese-inspired chicken broth

Beef bones: beef bone broth/stock, beef vegetable soup, Vietnamese beef pho

Fish/seafood scraps: fish or seafood broth, seafood bisque, fish and millet soup

Cheese rinds: minestrone, lentil soup, ribollita (also a good use for bread scraps), Roasted Garlic, Potato and Parmesan soup

Stale bread: pappa al pomodoro, pancotto, sopa Castellano, sopa de ajo

Greens and herbs: Tamar Adler’s Lettuce and Rice Soup, German green soup (aka Gründonnerstag or seven- or nine-green soup)

Broccoli/cauliflower/cabbages: broccoli and cheddar soup, curried cauliflower soup, Polish cabbage soup

Miscellaneous vegetable ends and peels (asparagus, carrots, green beans, winter squash and root veg, zucchini, etc.): Creamy Blended Vegetable Soup, Winter Root Vegetable Soup