Scrap Cooking: Broccoli Stems, Carrot Tops, and the Food You're Throwing Away

Picture the cutting board after a normal weeknight dinner. A thick broccoli stem. A feathery fistful of carrot tops. The leafy crowns off a bunch of beets. A handful of cilantro stems, the ribs you stripped out of a bunch of kale, a heap of potato peels, and the rind from the last wedge of Parmesan. Most of that goes straight into the trash or the compost bin without a second thought.

A surprising amount of it is perfectly good food. Some of it is genuinely more nutritious than the part you kept. And a couple of things on that list really should go in the bin, which is worth knowing before you get too enthusiastic about eating everything.

This is a practical guide to scrap cooking: what is worth saving, what to do with it, where the nutrition claims hold up and where they are oversold, and the short list of scraps that are not safe to eat.

What wasted food actually costs you

Start with the money, because it is bigger than most people assume. In April 2025, the EPA published an updated estimate of what uneaten food costs American consumers. It found that the average person wastes $728 a year on food that is bought but not eaten, or about $14 a week. Scaled to a household of four, that is $2,913 a year, or $56 every week, and roughly 11 percent of what an American spends on food. Fresh vegetables alone account for about 31 pounds and $59 of that waste per person per year.

One detail in that report matters for this post: the estimate counts only the edible parts of food. The broccoli stems and carrot tops you toss are not even in that $728. Scrap cooking is extra value on top of simply eating the groceries you already bought.

There is also an uncomfortable twist for anyone trying to eat well. A 2018 study in PLOS ONE used national diet survey data from 2007 to 2014 and found that US consumers wasted about 422 grams of food per person per day, with fruits and vegetables making up 39 percent of it. People with the highest-quality diets wasted more food, about 535 grams a day compared with 295 grams for people with the lowest-quality diets, largely because produce spoils faster and gets trimmed more. The researchers concluded that teaching people how to prepare and store fruits and vegetables is one of the practical ways to cut waste.

In other words, the healthier your shopping cart, the more you stand to gain from learning what to do with the parts you usually throw away.

Broccoli stems (and the leaves nobody talks about)

You will often hear that broccoli stems are "even better than the florets." The research does not quite support that, and it is worth being precise.

A 2018 study in the journal Molecules compared the florets, stems, and leaves of broccoli. The florets had about 34.7 micromoles of total glucosinolates per gram of dry weight, compared with about 7.5 in the stems. Glucosinolates are the sulfur compounds behind much of broccoli's reputation, so on that measure the florets win by more than four to one. Florets also carried roughly 12 times the carotenoids of the stems. One exception: the stems had 10 times more of a specific glucosinolate called glucoerucin than the florets.

So stems are not a secret superfood. They are still very much worth eating. A 2022 study in the International Journal of Molecular Sciences found that freeze-dried broccoli stalks were 38 percent dietary fiber by dry weight, most of it insoluble. They also have a mild, sweet, almost kohlrabi-like flavor that a lot of people end up preferring once they try them.

The real surprise in that 2018 study was the leaves. Broccoli leaves had about six times the carotenoids of the florets, the highest total phenolics of any part of the plant, and far more vitamin K. If your broccoli comes with a few leaves attached, as it often does at farmers markets, do not pull them off and throw them away. Cook them exactly like collards or kale.

How to use broccoli stems

• Peel first. The outer layer is tough and fibrous. Take it off with a vegetable peeler or a paring knife until you reach the pale green center.
• Slice into coins and cook with the florets. Cut them a little thinner than the florets so everything finishes at the same time in a stir-fry or on a sheet pan.
• Shred for slaw. Grated raw stems make a crunchy slaw with carrot, a little vinegar, and sesame oil. This is exactly what bagged "broccoli slaw" is.
• Cut into sticks for dipping. Peeled raw stem sticks hold up well to hummus.
• Blend into soup. Stems go right into broccoli soup, where their texture disappears completely.

Carrot tops

There is a persistent rumor that carrot greens are toxic. They are not. North Carolina State University Extension's plant database states plainly that carrot leaves, roots, flowers, and seeds are all edible, and suggests using the leaves in cooked dishes or pesto.

Carrot tops taste like a bitter, grassy cousin of parsley, which makes sense because carrots and parsley belong to the same plant family. That bitterness is the thing to plan around. They are too assertive to use as a salad green by themselves, but they are excellent when mixed with other herbs or tamed with fat, acid, and salt.

How to use carrot tops

• Carrot-top pesto. Swap half the basil for carrot greens. Blend with garlic, toasted walnuts or sunflower seeds, olive oil, lemon juice, and Parmesan. The half-and-half ratio keeps it from turning bitter.
• Chimichurri. Carrot tops work beautifully in place of some of the parsley, chopped fine with garlic, red wine vinegar, oregano, red pepper flakes, and olive oil. Spoon it over roasted carrots for a nice root-to-leaf moment.
• Green sauces and dressings. A small handful blended into a yogurt or tahini dressing adds color and an herby edge.
• Soups and stock. Use the thin stems in the scrap bag (more on that below).

Use only the finer leaves in raw sauces. Strip them off the thicker stems, which are stringy. And store the tops separately: cut them off the carrots as soon as you get home, because leaving them attached pulls moisture out of the roots.

Beet greens

When you buy beets with their leaves attached, you are getting a second vegetable for free. Beet greens are close relatives of Swiss chard (they are the same species, just bred for different parts), and they cook the same way.

Are they better than chard? It depends on what you are measuring. Per 100 grams raw, USDA data shows beet greens have 3.7 grams of fiber, 117 milligrams of calcium, 762 milligrams of potassium, and 2.6 milligrams of iron. Swiss chard has 1.6 grams of fiber, 51 milligrams of calcium, 379 milligrams of potassium, and 1.8 milligrams of iron. So beet greens come out well ahead on fiber, calcium, and potassium. Chard, on the other hand, has about twice the vitamin K and slightly more magnesium, and the two are nearly identical in vitamin A and vitamin C. Call it a draw with an edge to the greens you did not have to pay extra for.

One note: both are high in oxalates, so if you have been told to limit oxalates for kidney stones, treat beet greens the same way you would treat spinach or chard.

How to use beet greens

• Sauté with garlic. Slice the stems and cook them for two or three minutes first, then add the chopped leaves and cook until just wilted. Finish with lemon or a splash of vinegar.
• Stir into grains, beans, or pasta. Chopped greens wilt in a minute or two in anything hot.
• Add to frittatas and egg scrambles.
• Use soon. Beet greens wilt much faster than the roots. Cut them off, wrap them loosely in a damp towel, and cook them within a couple of days.

Kale and chard stems

Most recipes tell you to strip kale and chard leaves from their ribs and throw the ribs away. They are edible. They just take longer to cook than the leaves.

• Sauté them first. Slice the stems thin, like celery, and cook them with onion for five minutes before adding the leaves.
• Pickle them. Chard stems, especially the red and yellow ones, make pretty quick pickles. Pack sliced stems into a jar and cover with a hot brine of equal parts vinegar and water with a little salt and sugar. Keep them in the fridge.
• Blend them. Chopped stems disappear into smoothies, pesto, and blended soups.

Herb stems

The tender stems of cilantro, parsley, and dill carry as much flavor as the leaves. In Thai cooking, cilantro stems and roots are pounded into curry pastes on purpose. Chop soft herb stems finely and use them right along with the leaves in salsas, sauces, and salads, or save them for the stock bag.

Woody stems like rosemary and thyme are too tough to eat, but they are still useful. Toss them into a pot of beans, a braise, or stock for flavor and fish them out before serving.

Potato peels

Potato skins have a reputation for holding "all the nutrients." That is not quite true, but they do earn their place. USDA data for baked potatoes shows the skin has 7.9 grams of fiber and 7 milligrams of iron per 100 grams, compared with 2.2 grams of fiber and about 1 milligram of iron for the whole baked potato, flesh and skin together. Potassium is similar in both, and the flesh actually has slightly more folate. The simplest takeaway: leaving the skin on is an easy fiber win, and you skip a step.

How to use potato peels

• Don't peel at all. Scrub potatoes well and leave the skins on for roasted potatoes, mashed potatoes, and soups.
• Crispy peel chips. If a recipe does call for peeled potatoes, toss the peels with a little olive oil and salt, spread them on a sheet pan in a single layer, and bake at 400°F for about 15 to 20 minutes, until crisp. Eat them the same day.

Wash any peel you plan to eat. The FDA recommends that you scrub firm produce with a clean brush under running water and skip soap or commercial produce washes, which can be absorbed by the produce.

And one hard rule, covered in more detail below: do not eat potato skin that has turned green.

Parmesan rinds

That hard end of a wedge of Parmesan is one of the best flavor boosters in your kitchen. According to the Parmigiano Reggiano consortium, the rind of Parmigiano Reggiano is edible because the cheese is made only of milk, salt, and rennet and the rind gets no preserving treatment. It is simply the outer layer of cheese that dried as it aged. The consortium does suggest cleaning the rind well before using it.

The rind is too hard to eat as is, but it softens as it simmers. Drop one into a pot of minestrone, white bean soup, tomato sauce, or risotto broth and let it cook for at least half an hour. It adds a deep, savory flavor and a bit of body. Fish out whatever is left before serving.

Keep rinds in a bag in the freezer and grab one whenever you make soup. If you are using a domestic "parmesan-style" cheese, check that the rind is not waxed or coated before you put it in the pot.

Citrus zest

This is the easiest habit on the list: zest your lemons, limes, and oranges before you juice them. Once the fruit is squeezed and floppy, zesting is nearly impossible.

Lemon peel is nutritionally dense, with USDA data showing 10.6 grams of fiber and 129 milligrams of vitamin C per 100 grams. To be honest about it, though, you only use a few grams of zest at a time, so this is mostly a flavor win, not a nutrition one. And it is a big flavor win. Zest carries the fragrant citrus oils that juice does not have.

• Zest onto a small piece of parchment, fold it into a packet or small container, and freeze. It keeps its aroma well.
• Rub zest into sugar for baking, stir it into yogurt, or add it to vinaigrettes, marinades, roasted vegetables, and grain salads.
• Wash citrus before zesting, following the same FDA produce-washing guidance above.

The freezer scrap bag for stock

This is the system that makes everything else easier. Keep a large zip-top bag or container in the freezer. Every time you prep vegetables, drop in the trimmings that are clean but not worth eating on their own: onion ends and skins, celery bases and leaves, carrot peels and ends, leek greens, mushroom stems, herb stems, and the woody stalks of broccoli if you did not use them.

When the bag is full, dump it into a large pot, cover with cold water, add a bay leaf and some peppercorns, and simmer for about 45 minutes to an hour. Strain, and you have free stock.

A few tips that make scrap stock taste better:

• Onion skins add color. They give stock a deep golden brown color. Use a few, not a whole bag's worth, since too many can turn it bitter.
• Go easy on cabbage-family scraps. A lot of broccoli, cauliflower, cabbage, or Brussels sprout trimmings can make stock taste sulfurous.
• Beet peels will turn everything pink.
• Only freeze clean scraps. Nothing moldy, slimy, or spoiled. The scrap bag is for trimmings, not for food that has already gone bad.

Chicken bones go in their own bag. After a roast chicken or rotisserie chicken, freeze the carcass and make chicken stock when you have two or three.

Cool homemade stock quickly. Penn State Extension recommends that you divide stock into multiple small containers so it cools to room temperature within two hours, then refrigerate it for up to three days. For longer storage, freeze it in containers with some headspace to allow for expansion. Do not try to preserve stock in a water-bath canner. Low-acid broth has to be pressure canned.

Scraps you should actually throw away

Scrap cooking is credible only if it comes with a clear list of exceptions. These are the important ones.

Rhubarb leaves

Rhubarb stalks are great. The leaves are not food. MedlinePlus, from the National Library of Medicine, lists oxalic acid and possibly anthraquinone glycosides as the poisonous ingredients in rhubarb leaves and notes that only the stalk can be eaten. Symptoms of poisoning include burning in the mouth and throat, nausea, vomiting, diarrhea, and stomach pain, and severe cases can involve breathing difficulty, seizures, and kidney damage. Do not put rhubarb leaves in pesto, stock, or anything else.

Green potatoes and potato sprouts

When potatoes are exposed to light, they can turn green and build up solanine, a natural toxin. MedlinePlus says solanine is found throughout the potato plant, particularly in green potatoes and new sprouts, and advises never eating potatoes that are green below the skin and always throwing away the sprouts. Symptoms can include stomach pain, nausea, vomiting, and diarrhea.

This matters for scrap cooking because the green shows up first in the skin, which is the exact part you are now saving. Do not make peel chips from green-tinged peels. If a potato is mostly green or tastes bitter, throw it out. Store potatoes somewhere cool and dark to keep them from greening in the first place.

Anything that has actually gone bad

Using scraps is about eating good food you would otherwise waste, not about salvaging food that has spoiled. Moldy, slimy, or sour-smelling produce goes in the compost, not the stock pot.

The best scrap is the one you never have to rescue

Scrap cooking is satisfying, but it tackles only the tail end of the problem. The bigger losses in that EPA estimate are the whole vegetables, meat, and dairy that get forgotten in the back of the fridge because nobody planned a meal around them.

That is where planning does more than any clever pesto. When you decide what you will cook before you shop, you buy one bunch of kale for two meals instead of two bunches "just in case." You know the beet greens will go into Tuesday's frittata. You know Sunday's roast chicken bones will become Thursday's soup. The scraps get a plan too.

Eat Well Planner is built for this. You can save recipes from any website, Instagram reel, or YouTube video, let the AI build a weekly meal plan from them, and get an automatic shopping list with only what the plan actually needs. If you are staring at a pile of carrot tops, Recipe Discovery can search the web for recipes that use them, and the AI recipe chat can adapt a recipe you already love to work them in.

Scraps and plant diversity

If you are working toward eating 30 different plants a week for gut health, scrap cooking helps, though not quite in the way you might hope. A beet and its greens are the same plant, and so are a carrot and its tops, so eating the whole vegetable does not double your count.

What scrap cooking does is nudge you into dishes that naturally stack up variety. A carrot-top pesto with parsley stems, garlic, walnuts, and lemon zest brings several different plants into one spoonful. A scrap stock simmered with onion, celery, leek, mushroom, and herbs puts a little of all of them into every bowl of soup. Eat Well Planner's Plant Points feature tracks the different plants in your recipes and meal logs through the week, so you can see how those extra herbs, nuts, and seeds add up.

A simple weekly scrap routine

You do not need to turn every trimming into a project. A few habits cover most of it:

1. When you unpack groceries, cut the tops off carrots and beets and store the greens separately so they last.
2. Before you juice citrus, zest it and freeze the zest.
3. While you prep, keep a freezer bag open for stock scraps and a second one for Parmesan rinds.
4. Once a week, plan one meal that uses the greens and stems: a sautéed greens side, a pesto, a stir-fry with sliced broccoli stems, or a soup.
5. When the stock bag is full, make stock on a day you are already home, and freeze it in portions.
6. Know the exceptions: rhubarb leaves, green potatoes, potato sprouts, and anything spoiled go in the bin.

None of this requires a special diet or a lot of extra time. It is mostly a matter of looking at the cutting board a little differently. The broccoli stem is dinner. The carrot tops are a sauce. The rind is next week's soup. And the money you were throwing away with them stays in your pocket.

Ready to waste less and plan more? Try organizing your meals with Eat Well Planner, free to use, with shopping lists built from exactly what your week needs.