4-5 pounds of mixed beef bones. (neck, marrow, and knuckles are ideal)
Ice, approximately 2 pounds (optional, cold water will work as well)
1 large yellow onion, diced
2 small carrots, diced
1 small head of fennel, diced
1 sachet of aromatics (black peppercorns, thyme, parsley, bay leaves)
1. Assemble your ingredients.
2. Preheat your oven to 375 degrees.
3. Throughly rinse your bones with warm water to remove any blood or bone debris. Dry the bones, coat them with the canola oil and roast on a baking sheet for approximately 45 min or until the bones are golden brown. Turn bones over at least once during roasting to ensure even browning.
4. When the bones are finished roasting allow them to cool long enough to handle. Then, rinse the bones a second time with warm water to wash off any residual fat or coagulated proteins stuck to the bones.
5. Transfer the bones to a stock pot large enough to accommodate the bones with plenty of headroom.
6. Cover the bones with a generous amount of ice (this step is optional and will yield a more clear broth, if you don't have ice, just use cold water). They should be completely covered. If possible work the ice down into the stock pot and between the bones so that the ice is evenly distributed throughout the pot.
7. Cover the bones with cold water, they should be completely submerged. You want the water to go from as cold as possible to the final cooking temperature over an extended period of time. This will slowly extract flavor and nutrients from the bones and ensure an unctuous, flavorful, nutritious and crystal clear bone broth.
8. Place the broth over a medium burner and slowly bring the contents up to 190 degrees. Once at temperature, turn the burner down to its lowest setting. Maintain this temperature, which should look like a very light simmer, for 6-8 hours.
9. While the broth cooks, skim off any foam that rises to the surface every hour or so. This foam is the proteins coagulating and rising to the surface. If you were to boil your broth these coagulants and any remaining fat would cloud your broth, capture many of the nutrients in your stock, and basically leave you with a cloudy, unappetizing bone-flavored water.
10. When you’re satisfied that you have skimmed off all of the “impurities”, pitch in your aromatics (your onion, carrot, fennel, and if you choose add the bouquet of herbs). The aromatics will have imparted their flavor and nutrients to the broth after one hour.
11. Strain your broth through a conical sieve or basic kitchen strainer. If you want an even clearer broth, strain the broth a second time through a cheesecloth lined strainer.
12. Chill immediately. The broth will keep for up to 5 days refrigerated or up to two months frozen.