Turn Kitchen Scraps Into Free Broth

Every time you cook, you throw away the start of a pot of broth. Onion ends, carrot peels, the leafy tops of celery, a fistful of parsley stems. On their own they look like trash. Saved up in the freezer, they're a free pot of broth that makes soup, rice and beans taste better than water ever could.

This guide covers what to save, what to skip, how to simmer it, and how to store it safely. There's an optional upgrade box near the end with a few storage helpers, but a freezer bag and a pot you already own are all you need.

Why it's worth saving scraps

You already paid for those peels and ends. Turning them into broth means you get one more use out of groceries you bought anyway, instead of buying cartons or bouillon. Homemade broth also lets you control the salt, which is handy if you're watching it or cooking for kids.

And it's less waste. Scraps that would've gone to the trash become dinner first, and then whatever's left can still go to the compost. That's two lives for the same onion.

The free way, step by step

Step 1: Start a scrap bag

Grab a zip-top bag or a leftover takeout container with a lid, and put it in the freezer. Every time you prep vegetables, add the clean trimmings. Freezing stops them from going slimy while you collect, so there's no rush.

Wash produce before you peel or trim it, so the scraps going into the bag are clean. A quick rinse and scrub is enough.

Step 2: Save the right scraps

These all make a mild, all-purpose broth:

• Onion ends and skins. The papery skins add a lovely golden color.
• Carrot peels and tops. Sweetness and body.
• Celery ends and leaves. The leaves are packed with flavor.
• Herb stems. Parsley, cilantro, thyme and dill stems all work.
• Mushroom stems. Deep, savory flavor.
• Garlic skins and ends. A little goes a long way.
• Leek greens. The tough dark tops you'd usually toss. Rinse out any grit first.
• Chicken bones (optional). Bones from a roast chicken turn it into chicken broth. Freeze them in the same bag or a separate one.

Step 3: Know what to skip

• Broccoli, cabbage, Brussels sprouts and their cousins. These brassicas can make broth bitter or sulfurous. Skip them or keep them to a tiny amount.
• Potato peels. They're starchy and can turn broth cloudy.
• Anything moldy, slimy or spoiled. Broth is a way to use scraps, not a way to rescue food that's gone bad.
• Strong flavors in large amounts. A pile of beet peels will turn everything pink. A little is fine if you like it.

Step 4: Simmer when the bag is full

Once your bag or container is full, it's broth day. Dump the frozen scraps straight into a big pot. No need to thaw. Add enough cold water to cover them by an inch or two, and toss in a bay leaf. A few whole peppercorns are nice too if you have them.

Bring it up to a gentle simmer, cover, and let it go for 1 to 2 hours. A gentle simmer, with small bubbles, keeps the broth clearer than a hard boil. Taste it along the way. When it tastes like something you'd want to cook with, it's done. If you added chicken bones, you can let it go on the longer end for a richer broth.

Hold off on the salt. Unsalted broth is more flexible, and you can season the soup or rice you use it in later.

Step 5: Strain

Set a colander or strainer over a big bowl or a second pot and pour the broth through. Press on the scraps gently with a spoon to get the last of the liquid out. If you want it clearer, pour it through again with a clean, thin kitchen towel lining the strainer.

Step 6: Cool it fast, then portion

This is the food safety step, so don't skip it. USDA guidance is to refrigerate cooked food within 2 hours. A big pot of hot broth cools slowly, so split it into shallow containers so it chills faster. Leave the lids off or cracked until the steam stops, then close them up.

Once it's cool, portion it the way you'll use it. Measured cups for recipes. Smaller amounts for deglazing a pan or loosening leftover rice. Label each container with the date.

Step 7: Compost what's left

The spent veggie scraps have given you everything they've got. Send them to the compost bin. No yard? Our guide to composting in an apartment has options that work in small spaces. Bones generally don't belong in a home compost bin, so those go in the trash.

Ways to use your broth

• Cook rice, quinoa or other grains in broth instead of water.
• Use it as the base for soups, stews and chili.
• Splash it into a pan to deglaze after browning meat or vegetables.
• Thin out leftover sauces, gravies or mashed potatoes.
• Simmer dried beans in it.

Planning meals around what you have is the best way to use up the broth before it expires. Our meal planning guide covers that.

Common mistakes

• Adding everything. One brassica-heavy batch tastes like old cabbage. Be picky about what goes in the bag.
• Boiling it hard. A rolling boil makes cloudy, muddy broth. Keep it at a gentle simmer.
• Cooling it on the stove overnight. Get it into shallow containers and into the fridge within 2 hours.
• Forgetting to label. Frozen broth all looks the same. Write the date on it.

When the upgrade is worth it (and when it isn't)

If you make broth once in a while, a zip-top bag and a colander are enough. If it becomes a regular habit, reusable silicone bags stop you from going through a stack of plastic ones, and a fine-mesh strainer gives you clearer broth with less fuss.

Freezer-safe containers or large ice cube trays are worth it if you want broth in handy, measured portions. Frozen cubes are great for deglazing a pan or making a single serving of rice. For more storage ideas, see our roundup of reusable food storage.