Prepare Beef: Slice the beef into thin strips, about 1/4 inch thick, against the grain for a tender texture. Trim any excess fat.
Marinate: In a mixing bowl, combine coconut aminos (or soy sauce), apple cider vinegar, Worcestershire sauce, garlic powder, onion powder, smoked paprika, black pepper, red pepper flakes, sea salt, and cayenne pepper. Mix well.
Marinate Beef: Place the beef strips in a large resealable bag or a shallow dish. Pour the marinade over the beef, ensuring all pieces are well-coated. Seal the bag or cover the dish and refrigerate for at least 4 hours or overnight for maximum flavor.
Preheat Oven or Dehydrator: If using an oven, preheat it to 175°F (80°C). If using a dehydrator, follow the manufacturer's instructions for drying meat.
Arrange Beef: Place a wire rack on a baking sheet if using an oven. Arrange the marinated beef strips on the wire rack in a single layer, making sure they do not overlap.
Dry Beef: Place the baking sheet in the preheated oven or the beef strips in the dehydrator. Dry for 4-6 hours, or until the beef jerky is dry and chewy but still slightly pliable.
Cool and Store: Remove the beef jerky from the oven or dehydrator and let it cool completely. Store in an airtight container or resealable bag. It can be kept at room temperature for a few days or refrigerated for longer shelf life.