Slow-cooker bone broth
- 5 lbs 2.3 kg beef bonebeef bones or lamb bone, or a combination of the twolamb bones, or a combination of the two
- 2 2 yellow onionyellow onions (optional)
- 2 2 carrotcarrots or celery root (optional)
- 1 1 whole garlicwhole garlics (optional)
- 2 tbsp 2 tbsp olive oil
- 2 tbsp 2 tbsp unsweetened tomato sauce (optional)
- salt and pepper
- fresh thyme or fresh parsley (optional)
- 1½ cups 350 ml water, plus extra for boiling
- 2 tbsp 2 tbsp cider vinegar
- Preheat the oven to 450°F (225°C).
- Place bones and optional vegetables in a baking dish with sides. You don't have to peel the garlic cloves, just crush them a little. Pour olive oil over and add spices. Add tomato sauce and mix to coat the bones and the vegetables.
- Roast until the bones and the vegetables are properly browned. This will take about 1–1.5 hours; turn once, about half way through. Add a cup or two of water towards the end to prevent the juices and flavors accumulating in the dish from burning.
- Empty the contents of the baking sheet into a big pot. Add water to cover the contents by a few inches and add the vinegar. Boil for 10–15 minutes. Lower the heat and let simmer for many hours, anything from 8-24 hours will work fine. The broth is done when it's deep brown in color and deeply flavorful.
- Now it's time to remove the bones and vegetables (use a strainer).
- Simmer to reduce the bone broth to 75–25 percent, depending on whether you want it ready to drink, or ready to freeze in concentrated small cubes. Add salt and pepper to taste.
- Cool the broth to room temperature and refrigerate. The broth may become solid and jelly-like once cooled. This is perfectly normal. It will melt again when heated. The broth will last for up to five days in the fridge and for about three months in the freezer.
We recommend using a large spaghetti pot with a strainer, and then you can just remove the contents when finished simmering. After the reduction, you may run the broth through a sieve to remove smaller pieces.