Stop throwing away kitchen scraps. Here are 16 ways to use apple cores, banana peels, coffee grounds, eggshells, and more.
Zero waste, zero cost.
Most of us throw away a third of every ingredient we buy.
Not the spoiled parts. Not the mouldy bits. The good parts…carrot tops, citrus peels, parmesan rinds, coffee grounds, eggshells, banana skins all scraped into the bin without a second thought because nobody ever told us what else to do with them.
The average household wastes $900 worth of food every year. A significant chunk of that is scraps that were never actually waste — they were ingredients waiting for a second use.
This guide covers 16 of the most common kitchen scraps and exactly what to do with each one. No complicated techniques. No specialist equipment. Just practical uses you can start today.
The Scrap bag Rule — start here
Before anything else, do this: put a zip-lock bag or container in your freezer. Every time you prep vegetables, peel fruit, or finish a roast, anything that would have gone in the bin goes in the bag instead.
Onion skins. Herb stems. Carrot peels. Parmesan rinds. Garlic skins. Leek tops. Celery ends. Mushroom stalks.
When the bag is full, make your broth. Simmer everything with cold water for 45 minutes, strain, season, and freeze in portions. That’s liquid gold for soups, risottos, grains, and sauces.
This single habit eliminates the majority of vegetable waste in any kitchen. Everything else in this list builds on top of it.
16 Kitchen Scraps and What To Do With Them
1. Apple Cores and Peels
Apple scraps are one of the most versatile things in your kitchen and almost universally thrown away.
Homemade apple cider vinegar. Fill a jar with apple cores and peels. Cover with water and one tablespoon of sugar per cup of water. Cover with a cloth secured with a rubber band and leave at room temperature. Stir daily. After two to four weeks it will smell vinegary — strain, bottle, and use within six months. This is the same ACV that costs $8 a bottle at the health food shop.
Wild yeast bread starter. Apple skins carry natural wild yeast. Add them to a flour and water mixture and you have the beginnings of a sourdough starter.
Natural pectin for jams. Simmer apple scraps in water, strain the liquid, and add it to any jam that needs help setting. Apple pectin is natural and free.
2. Banana Peels
Banana peels are the most underused scrap in most kitchens.
Pulled pork substitute. Slice the peels into strips, toss with smoked paprika, soy sauce, cumin, and olive oil, and roast at 220°C for 20 minutes until caramelised. Serve in tacos with slaw. The texture is genuinely remarkable.
Plant food. Soak banana peels in water for 48 hours and use the water on houseplants. High in potassium — exactly what plants need to flower and fruit.
Shoe polish. The inside of a banana peel polishes leather shoes. Rub on, buff off. It actually works.
3. Citrus Peels
Lemon, orange, lime, and grapefruit peels all have three solid uses beyond the bin.
All-purpose kitchen cleaner. Pack citrus peels into a jar, cover completely with white vinegar, seal, and leave for four weeks. Strain, dilute 1:1 with water, and add ten drops of tea tree oil. This cleans and deodorises every surface in your kitchen without plastic packaging or harsh chemicals.
Candied peel. Simmer citrus peel strips in equal parts sugar and water for 30 minutes, drain, and dry on a rack. Dip in dark chocolate or use in baking.
Natural food colouring. Dried and powdered orange or lemon peel adds colour and flavour to baked goods, smoothies, and spice blends.
4. Coffee Grounds
Used coffee grounds have three uses that most people miss completely.
Face and body scrub. Mix used grounds with coconut oil and a pinch of salt. Scrub in the shower. Caffeine tightens and brightens skin temporarily — the same ingredient in expensive body scrubs.
Garden fertiliser. Sprinkle directly on soil around acid-loving plants like blueberries, roses, and tomatoes. Coffee grounds improve drainage and add nitrogen.
Fridge deodoriser. Leave a small bowl of dry used grounds in the fridge. Absorbs odours better than baking soda.
5. Parmesan Rinds
If you throw away parmesan rinds you are throwing away the most flavourful part of the cheese.
Simmer in soups and stews. Drop a rind into any soup, stew, or tomato sauce as it cooks. It melts slowly and releases a deep umami flavour that transforms the dish. Remove before serving.
Pasta sauce base. Simmer a rind in your tomato sauce for 30 minutes. The depth of flavour it adds is why restaurant pasta sauce tastes different from home-cooked.
Slow cooker beans. Add a rind to dried beans as they cook. The beans absorb flavour and become silkier.
6. Onion Skins
The papery outer skins of onions are thrown away by almost everyone and used by almost no one — which is a waste because they are flavourful and useful.
Broth colour and depth. Add onion skins directly to your scrap bag or broth pot. They turn the broth a beautiful golden-brown colour and add a savoury depth.
Natural fabric dye. Simmer onion skins in water for an hour and you have a natural yellow-orange dye that works on natural fabrics. No chemicals needed.
Liquid fertiliser tea. Soak onion skins in water for 24 hours and use the liquid to water plants. Onion skins are rich in quercetin and plant-beneficial compounds.
7. Garlic Skins
Garlic skins are the scraps most people never consider keeping.
Add to broth. Garlic skins add depth and mild garlic flavour to any broth. Just throw them straight into the scrap bag.
Roast until crispy. Toss garlic skins in a little olive oil and roast at 180°C for 8-10 minutes until crispy. Use as a garnish or crumble over salads for a subtle garlic crunch.
Freeze for the next batch. They keep indefinitely in the freezer and are ready whenever you make broth.
8. Chicken Bones
A roasted chicken carcass is not food waste. It is the starting point for the best broth you will ever make.
Master broth. Place the carcass in a large pot with your frozen scrap bag contents, a splash of apple cider vinegar (it draws minerals from the bones), and enough cold water to cover. Bring to a gentle simmer, never a rolling boil. Simmer for two to four hours. Strain through a fine sieve. Season generously with salt. Refrigerate for up to five days or freeze for three months.
Use this broth to cook grains, as a base for any soup, to deglaze roasting pans, or drink it warm as a mineral-rich tonic.
9. Eggshells
Eggshells are almost entirely calcium carbonate and have three uses in the garden and kitchen.
Calcium for garden soil. Crush eggshells and dig into the soil around tomatoes and peppers. Prevents blossom end rot, which is caused by calcium deficiency.
Slug deterrent. Crushed eggshells around seedlings create a barrier that slugs avoid crossing. Free and chemical-free pest control.
Seed starter cups. Half an eggshell with a small drainage hole makes a perfect biodegradable seed starting cup. Plant the whole thing in soil when the seedling is ready.
10. Leftover Oatmeal
Cooked oatmeal that didn’t get eaten has more uses than you’d expect.
Pancakes and waffles. Replace half the flour in any pancake or waffle recipe with leftover oatmeal. The texture is better and the pancakes are more filling.
Muffins and cookies. Add a few tablespoons to muffin or cookie batter. Adds moisture and binding.
Freeze in portions. Leftover oatmeal freezes perfectly. Reheat from frozen with a splash of milk. Faster than cooking from scratch.
Use as a fresh herb. Parsley stems and coriander stems are fully edible and flavourful. Chop them finely and use exactly as you would the leaves.
11. Vegetable Cooking Water
The water you boil or steam vegetables in is full of nutrients and flavour that most people pour straight down the drain.
Gravy base. Use it instead of water or stock when making gravy. The starch from potato or pasta water also helps the gravy thicken naturally.
Broth boost. Add it directly to any soup or stew for extra depth.
Cook grains in it. Use vegetable cooking water instead of plain water when cooking rice, quinoa, or lentils. The grains absorb the flavour and become noticeably more interesting.
12. Herb Stems
Herb stems — parsley, coriander, basil, thyme, rosemary — are thrown away constantly despite being entirely edible.
Infuse oils and vinegars. Pack herb stems into a bottle of olive oil or white wine vinegar. Leave for two weeks. Strain. Flavoured oil and vinegar for zero cost.
Add whole to broths. Throw stems straight into any broth or soup as it simmers. Remove before serving.
13. Avocado Pits
Most people don’t know avocado pits have any use at all.
Dry and grate as a mild spice. Leave the pit to dry for a week, then grate it on a fine grater into smoothies, soups, or dressings. It has a mild, slightly bitter, nutty flavour.
Natural rose-pink dye. Simmer avocado pits in water for an hour and you have a blush-pink natural dye for fabric, paper, or Easter eggs.
Grow an avocado plant. Pierce with toothpicks, suspend over a glass of water with the flat end down. Roots appear in two to six weeks.
14. Stale Bread
Bread that has gone stale is not bread that has gone off. It is bread that is ready to become something better.
Breadcrumbs. Blitz stale bread in a food processor and freeze in a bag. Use for coatings, toppings, and binders in everything from pasta to meatballs. Buy these at the shop and you’re paying $4 for something you were about to throw away.
Croutons. Cube, toss with olive oil, garlic, and salt, and bake at 200°C for 12 minutes until golden. Add to salads, soups, and grain bowls.
Bread pudding or panzanella. Stale bread is essential to both of these dishes. Soft fresh bread doesn’t work — only stale does.
15. Butternut Squash Seeds
Every time you cut open a butternut squash or pumpkin and scrape the seeds into the bin you are throwing away a genuinely delicious snack.
Rinse, season, and roast. Wash the seeds, pat dry, toss with olive oil, salt, and any spice you like — cumin, smoked paprika, cinnamon — and roast at 180°C for 15 minutes until golden. Better than any seed mix from the shop.
Add to granola. Mix roasted seeds into homemade granola for extra crunch and protein.
16. Coconut Oil (When it Goes Rancid)
Coconut oil that has gone rancid is no longer good for cooking — but it still has uses.
Wood conditioner. Rub rancid coconut oil into wooden cutting boards and utensils. Let it soak in overnight. It conditions the wood and prevents cracking.
Body scrub base. Mix with sugar or salt for a moisturising body scrub.
The Bigger Picture
About 43% of food waste occurs at home, not in restaurants or supermarkets. That means the most effective place to reduce food waste is in your own kitchen, with your own habits.
None of the uses above require specialist equipment, significant time, or any money. They just require seeing scraps as ingredients rather than waste , which is a mindset shift more than a skill.
The freezer scrap bag is the single most effective place to start. Once that habit is in place, everything else follows naturally.
Want the complete guide?
This article covers 16 scraps. The Scrappy Kitchen Blueprint covers all of this and more — 35 pages of zero-waste cooking systems, batch cooking methods, fermentation basics, eco kitchen swaps, and 15+ complete recipes.
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5 Ways to Use — Zero Waste Kitchen 
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