As per Bhava Prakasha, desi cow bilona ghee stored for one year or more in an air tight container is called Purana Ghrita or Purana Ghee.
What are the benefits of Purana Ghrita ?
Aged ghee or old ghee is known to cure numerous diseases, increase vitality and is an elixir of life. It is also good for skin ailments like eczema and patches.
Close to 8 year old ghee is available at Hetha. Gir and Sahiwal cow's A2 cultured bilona Ghee.