Ingredients:

  • 1 kg Beef Marrow Bones/Knuckles (about 2.2 lb)
  • 1 large Yellow Onion (150 g), roughly chopped
  • 2 medium Carrots (120 g), roughly chopped
  • 2 medium Celery Stalks (80 g), roughly chopped
  • 2 Tbsp Tomato Paste
  • 1 Tbsp Neutral Oil (e.g., Rapeseed/Canola)
  • 250 ml Dry Red Wine (1 cup), such as Merlot or Cabernet
  • 5 litres Cold Water or Low-Sodium Beef Stock (10 cups)
  • 4 sprigs Fresh Thyme Sprigs
  • 2 Bay Leaves (Dried)
  • 1 tsp Whole Black Peppercorns
  • Salt (Kosher or Fine Sea Salt), to taste
  • 60 ml Beef Roast Pan Drippings (optional, 4 Tbsp)

Instructions:

  1. Roast the Bones: Preheat oven to 220°C (425°F). Place the beef bones on a roasting tray and roast for 30–40 minutes, turning halfway, until deeply caramelised and dark brown. This is crucial for color and depth.
  2. Sauté the Mirepoix: While bones roast, heat the oil in a large stockpot over medium-high heat. Add the onion, carrots, and celery (the mirepoix). Sauté until deeply softened and lightly browned (about 10 minutes).
  3. Add Tomato Paste: Stir in the tomato paste and cook for 2 minutes, stirring constantly. This caramelises the paste and removes any raw taste.
  4. Deglaze: Pour in the red wine. Scrape up any browned bits (fond) stuck to the bottom of the pot. Reduce the wine by half (about 5 minutes) until syrupy.
  5. Combine Ingredients: Add the roasted bones, cold water (or stock), thyme, bay leaves, and peppercorns to the pot. Start with cold liquid to extract maximum flavor slowly.
  6. Simmer: Bring the mixture slowly to a gentle simmer. Once simmering, immediately reduce the heat to the lowest possible setting. Do not boil vigorously; a bare bubble is all you want.
  7. Skim the Impurities: As the jus simmers, use a ladle or spoon to constantly skim off any foam or scum that rises to the surface. This ensures a clean, clear finish.
  8. Cook Down: Simmer uncovered for a minimum of 2 hours, or up to 3 hours, until the liquid has reduced by about one-third and smells intensely meaty.
  9. Strain: Remove the pot from the heat. Carefully strain the liquid through a fine-mesh sieve (preferably lined with muslin or cheesecloth) into a clean saucepan. Discard the solids.
  10. Reduce and Refine: Return the saucepan to medium heat. Bring the jus to a steady simmer and reduce until it coats the back of a spoon lightly—this concentrates the flavor further.
  11. Skim the Fat (Crucial Step): Using a ladle or a fat separator, meticulously skim any remaining rendered fat from the surface. True Au Jus should be rich but not greasy.
  12. Incorporate Drippings (Optional): If you are serving the jus with a roast, stir in the reserved pan drippings now.
  13. Season and Serve: Taste the jus. Season generously with salt and pepper until the flavor 'pops.' Serve immediately, or cool quickly and chill.