2poundsbones (lamb, beef, chicken, fish; see note)
1/4cupapple cider vinegar
1gallonwater, or whatever amount your slow cooker will hold
4-6sprigsfresh parsley (about 1⁄4 cup)
4-6sprigsfresh thyme or 1 tablespoon dried
2springsfresh rosemary or 1 tablespoon dried
2sprigsfresh sage or 1 tablespoon dried
1bay leaf
Instructions
Combine the bones and vinegar in a slow cooker with enough water to cover by at least an inch. Cook on high until the liquid begins to simmer, then reduce the heat to low and cook for at least 48 hours and up to 72 hours — the longer the better. As the broth cooks, the water level will reduce; add hot water as needed to keep the level of the water above the bones. Don’t worry if the bones float to the top of the broth; that’s different than there not being enough liquid to cover them.
When the broth is 2 to 3 hours away from being done, add the parsley, thyme, rosemary, sage, and bay leaf.
When it is done cooking, turn off the heat and let cool slightly. Put a colander over a soup pot and pour the contents of the broth through the strainer. The broth will end up in the pot below, and the bones and herbs will remain in the colander.
Let the broth cool completely before transferring to containers and storing in the refrigerator or freezer. It will keep in the fridge for up to 1 week and in the freezer for up to 6 months.