Partially freeze the beef. Place the trimmed beef in the freezer for 45–60 minutes until firm but not rock solid. This makes it easier to slice thinly and evenly.

Slice against the grain. Using a sharp knife, slice the beef into 1/8–1/4 inch thick strips. Thinner slices dry faster and become chewier; thicker slices are meatier. Aim for uniform thickness for even drying.

Mix the marinade. In a bowl, combine coconut aminos or tamari, apple cider vinegar, Worcestershire, salt, pepper, smoked paprika, garlic powder, onion powder, red pepper flakes, and cumin. Taste and adjust salt if needed.

Marinate the beef. Add the slices to a zip-top bag or dish, coat well, and press out excess air. Marinate in the fridge for at least 4 hours, ideally 8–12 hours. Longer marination equals deeper flavor.

Pat dry. Remove the beef from the marinade and pat each piece dry with paper towels. Dry surfaces dehydrate faster and prevent steaming in the air fryer.

Preheat the air fryer. Set to 170–180°F (75–82°C) or the lowest setting your model allows. If your air fryer runs hot, lean toward the lower end to avoid cooking instead of drying.

Arrange the strips. Lightly oil or spray the basket or racks. Lay the beef in a single layer with space between pieces. Do not overlap, or the jerky will dry unevenly.

Air fry low and slow. Cook for 2.5–4 hours, flipping or rotating racks every 45–60 minutes. Timing varies by thickness, humidity, and air fryer model. Keep an eye on color and texture.

Check for doneness. Jerky is done when it’s dry to the touch, darker, and bends with a slight crack but doesn’t snap. Tear a piece; the inside should look fibrous, not raw or wet.

Cool and condition. Let jerky cool on a rack. For best shelf stability, “condition” it: pack loosely in a clean jar for 24 hours, shaking once or twice. If you see moisture on the glass, it needs more drying.