Begin by bringing a large pot of salted water to a rolling boil over high heat. Once boiling, add the rotini noodles and cook according to package instructions until al dente, usually about 8-10 minutes. Drain the noodles in a colander, then rinse them with cold water to halt the cooking process and prevent mushiness.

Transfer the cooled rotini noodles to a large mixing bowl. Pour in 1/3 cup of dill pickle brine, stirring gently to ensure the pasta absorbs the tangy flavor. Allow the noodles to sit for about 10 minutes.

Chop the dill pickles into small, uniform pieces, and dice the Colby Jack cheese into bite-sized cubes. Then, mince the white onion finely.

After the noodles have absorbed the pickle brine, drain any excess liquid if necessary. Add the chopped dill pickles, diced cheese, and minced onion to the bowl with the noodles. Gently fold the ingredients together until well combined.

In a separate bowl, whisk together the mayonnaise, sour cream, remaining pickle brine, freshly chopped dill, salt, and black pepper. Mix until smooth and creamy.

Pour the prepared dressing over the pasta mixture and stir gently to coat all the ingredients evenly.

Cover the bowl with plastic wrap and refrigerate the Dill Pickle Pasta Salad for at least 1-2 hours before serving.