How to Make Stock from Kitchen Scraps (Zero Waste Cooking)

Every time you throw away onion skins or chicken bones, you're throwing away flavour. Homemade stock transforms kitchen scraps into liquid gold—and it's easier than you think.

The Scrap Collection System

Keep a bag or container in your freezer. Every time you prep vegetables or break down a chicken, add the scraps. When the bag is full, you're ready to make stock.

What to Save

Great for Stock

• Onion skins and ends
• Carrot peels and tops
• Celery leaves and ends
• Leek tops (green parts)
• Mushroom stems
• Parsley stems
• Garlic skins
• Fennel fronds
• Corn cobs
• Chicken bones and carcasses
• Beef or pork bones

Use Sparingly

• Brassicas (cabbage, broccoli, cauliflower)—can make stock bitter
• Beetroot—will turn everything pink
• Turnips and parsnips—strong flavour

Avoid

• Potato peels—make stock starchy and cloudy
• Anything mouldy or rotten
• Overly spicy vegetables (unless you want spicy stock)

Basic Vegetable Stock

1. Add 1-2kg of scraps to a large pot
2. Cover with cold water (about 3 litres)
3. Add peppercorns, bay leaf, and a splash of vinegar
4. Bring to a boil, then simmer for 1-2 hours
5. Strain and discard solids
6. Season lightly with salt

Chicken Stock

1. Start with a chicken carcass (or bones from 2-3 thighs)
2. Add vegetable scraps
3. Cover with cold water
4. Add peppercorns, bay leaf, thyme
5. Simmer for 2-4 hours (longer = richer)
6. Strain, cool, and skim fat if desired

Rich Beef Stock

1. Roast bones at 200°C for 45 minutes first (crucial for flavour)
2. Transfer to pot with vegetable scraps
3. Cover with water and add tomato paste
4. Simmer for 4-8 hours
5. Strain and reduce if needed

Storing Your Stock

• Refrigerator: Up to 5 days in airtight container
• Freezer: Up to 6 months
• Pro tip: Freeze in ice cube trays for small portions
• Pro tip: Reduce stock by half before freezing to save space

Using Homemade Stock

• Base for soups and stews
• Cooking liquid for grains (rice, quinoa)
• Deglazing pans for sauces
• Adding depth to braises
• Making risotto
• Boosting instant noodles

The Environmental Impact

By making stock from scraps, you're:

• Reducing food waste
• Avoiding packaging from stock cubes/cartons
• Getting better nutrition (minerals from bones)
• Saving money (it's essentially free)

Making the most of every ingredient? Fridgr helps you reduce waste by tracking what you have and suggesting recipes.