Rinse the marrow bones clean. Place in a large pot and fully submerge them in water. Bring the water to a boil on high heat. Don’t want to cook the bones at this time. You only want to blanch them to remove impurities, so once the water starts boiling, drain it out and thoroughly rinse the bones again.
Roasting your bones before cooking will make your broth richer and add an extra layer of deep rich roasted flavor. Roast the bones by drying them with paper towel, season with salt, and arrange in a roasting pan.
Roast uncovered in a hot oven at 400 degrees F for 45 minutes until marrow bones turn a golden caramelized color. If you do not have an oven, you can caramelize your bones by searing them in a hot skillet with a bit of oil.
Once the roasted bones are golden brown, take them out of the oven and place them in a heavy stockpot. You should also add to the pot any drippings released by the bones during the roasting process.
Add enough cold water to the pot to submerge the bones and then add onion, garlic, salt, black peppercorns, and a splash of cider vinegar. These ingredients will flavor the bones to give you a tasty broth. You can also add carrots, green pepper, celery, and bay leaves to make your broth even more flavorful.
Place the pot on your stove top and set the heat to high. Once the pot starts to boil, cover it and reduce the heat to low. Let the broth cook for at least 8 hours. During cooking, check on the broth every couple of hours to see if you need to add more water to submerge the bones. This is especially important if you are cooking for those long periods of time. Some chefs suggest putting the pot in the oven overnight at about 220° F.
Another option is to make your beef bone broth in a slow cooker. To make a slow cooker beef bone broth, all you have to do is roast the bones and place them in the slow cooker with vegetables and other ingredients. Add water to submerge the bones, then put your slow cooker on low heat for 24 hours, checking on the broth periodically and when the cooking time ends.
Once cook time is complete, remove the bones from the broth. Pour the broth through a mesh strainer to remove the veggies and other ingredients you used as seasonings. Your broth should be completely strained and have a rich golden color.
You can store your strained broth in a food-safe container and let it cool. When bone broth cools, it will develop a jelly-like firmness due to its high gelatin content. You can immediately use your freshly made bone broth or store it in the fridge for five days. If you want to store your broth for longer, keep it in a below-zero degrees Fahrenheit freezer.
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