Combine Ingredients: In a bowl or mixing container, whisk together vinegar, fruit juice, soy sauce, olive oil, minced garlic, brown sugar (if using), black pepper, and paprika (if using). Stir until the sugar is dissolved and the ingredients are well-combined.
Adjust Flavor: Taste the marinade and adjust the seasoning to your liking. Add more sugar for sweetness, more vinegar for tanginess, or more soy sauce for saltiness. If you like a bit of spice, add chili flakes or a dash of hot sauce.
Marinate: Place your protein (chicken, steak, pork, tofu, etc.) or vegetables in a ziplock bag or shallow dish and pour the marinade over the top. Ensure the ingredients are well-coated. Seal the bag or cover the dish, and refrigerate for at least 30 minutes (or up to 12 hours for more flavor).
Cook: Once marinated, cook your ingredients on the grill, in the oven, or on the stovetop, depending on your preference. For grilling, brush the marinade over the food while it’s cooking for added flavor and moisture.
Serve: Once cooked, serve immediately and enjoy the delicious, flavorful results!