How to Make Bone Broth in a Slow Cooker: A Complete Step‑by‑Step Guide

Why Slow‑Cooker Bone Broth Works Best

Slow‑cookers extract collagen, minerals, and flavor from bones over hours, producing a nutrient‑dense broth that's gentle to digest. Unlike stovetop methods, the low, steady heat prevents scorching and ensures a clear, rich liquid.

Essential Ingredients and Supplies

Gather the following to start:

• 2–3 pounds of bones (beef, chicken, turkey, or a mix)
• 1 onion, quartered
• 2 carrots, chopped
• 2 celery stalks, chopped
• 2 garlic cloves, smashed
• 2 tbsp apple cider vinegar (helps draw minerals)
• Herbs: 2 bay leaves, 1 tsp whole peppercorns, optional thyme or rosemary
• Salt to taste (add after cooking)
• Water to cover

Equipment: a 6–8 quart slow cooker, a large pot for blanching bones, a colander, and a fine mesh strainer.

Step‑by‑Step Preparation

1. Blanch the Bones (Optional but Recommended)

Place bones in a pot, cover with cold water, bring to a boil for 10 minutes, then drain and rinse. This removes surface impurities and yields a clearer broth.

2. Assemble in the Slow Cooker

Transfer blanched bones to the slow cooker. Add onion, carrots, celery, garlic, vinegar, herbs, and salt. Pour enough cold water to cover everything by about an inch.

3. Cooking Time and Settings

Set the cooker to low and cook for 12–16 hours. If you're short on time, high for 6–8 hours still produces a good result but may be slightly cloudier.

4. Skimming (Optional)

After the first hour, skim off any foam or fat that rises to the surface with a ladle. This step is optional but results in a cleaner broth.

5. Strain and Store

When done, remove bones and solids with a slotted spoon. Strain the liquid through a fine mesh strainer or cheesecloth into a bowl. Let it cool, then refrigerate or freeze.

6. Final Seasoning

After cooling, skim any solidified fat from the surface. Add salt to taste. The broth can be used immediately or stored for up to 5 days in the fridge or 6 months in the freezer.

Tips for Maximizing Flavor and Nutrition

• Use a mix of marrow‑rich bones (e.g., marrow bones, oxtail) and meaty bones (e.g., chicken wings) for depth.
• Adding dried seaweed or kelp boosts iodine and mineral content.
• For a thicker consistency, simmer the strained broth for an additional hour on low.
• Use the broth as a base for soups, stews, risotto, or simply warm with a splash of lemon.

Common Questions Answered

Can I Use Frozen Bones?

Yes, frozen bones work fine. Just thaw them before blanching or add them directly to the slow cooker.

How Long Does the Broth Keep?

Refrigerated: 5 days. Frozen: 6 months. Always smell before reheating; if off, discard.

What If I Want a Clear Broth?

Blanching, skimming, and using a strainer are key. Avoid stirring during simmering to reduce cloudiness.

Quick Comparison: Slow Cooker vs. Stovetop