To embark on the pickling of walnuts, it is crucial to choose them while still in their green state, before the formation of a hard shell. Begin the process by wiping the walnuts clean, ensuring their surface is free from any impurities. Employ a pricking method, puncturing the walnuts well, and carefully discard any that feel firm to the touch. Place the prepared walnuts into a bowl, ready for the next step. Proceed by covering the walnuts with a brine solution, allowing them to soak for a duration of 8 days. Once this initial period has passed, discard the brine and proceed to cover the walnuts with a fresh brine, commencing a second soaking phase spanning 14 days. Following the completion of the second soaking period, thoroughly wash and dry the walnuts, ensuring they are prepared for the next stage. Arrange the walnuts, allowing them to be exposed to the air until they undergo a transformation and turn a deep shade of black. Prepare a batch of hot spiced vinegar in advance, as it will be needed for the next step. Carefully transfer the walnuts into pickle jars, ensuring they are well-packed. Proceed to cover the walnuts with the hot vinegar, ensuring their complete immersion. Once the jars have cooled, cover them securely. To attain the pinnacle of flavor, it is recommended to allow the pickled walnuts to mature for a period of 5 to 6 weeks before incorporating them into culinary creations.