Add 1 cup Worcestershire sauce and 1⁄4 cup maltodextrin to a small saucepan.
Whisk thoroughly to fully combine. Heat over medium, stirring frequently, until thickened to a paste consistency.
Spread paste evenly across a parchment-lined baking sheet. Bake at 200°F for 4-6 hours, stirring every 30 minutes, until completely dried.
Allow to fully cool. Transfer dried paste to a spice grinder, food processor, or mortar and pestle. Grind into a fine powder.
Transfer Worcestershire powder to an airtight container. Add remaining ingredients - dried onion/garlic powder, sea salt, allspice, and cloves. Shake vigorously to integrate flavors.
And your homemade Worcestershire powder is ready to use! For an even deeper flavor, let it rest 1 week before using. This allows time for the spices and aromatics to fully marry.