Cook the Pasta: Bring a large pot of salted water to a boil. Add 8 ounces of elbow pasta and cook according to package instructions until al dente, about 7-9 minutes. Once cooked, drain the pasta, rinsing it under cold water to cool it down and stop the cooking process. Set aside to let moisture evaporate.

Marinate with Dill Pickle Juice: In a mixing bowl, combine the cooked pasta with half of the dill pickle juice and soak for about 5 minutes. Drain any excess liquid to prevent the salad from becoming too watery.

Prepare the Dressing: In a large bowl, whisk together the mayonnaise, sour cream, remaining dill pickle juice, Sriracha (if using), salt, black pepper, and chopped fresh dill until smooth and creamy.

Combine Ingredients: In a large serving bowl, mix the marinated pasta, diced cheddar cheese, sliced dill pickles, finely chopped white onion, and remaining fresh dill, gently tossing to coat the pasta with the dressing.

Chill and Serve: Cover the bowl and refrigerate for at least 4-6 hours. When ready to serve, give the salad a gentle stir.