With green walnuts, spices, aromatic herbs, alcohol (of agricultural origin), and sugar, you can make ratafia, the herbal liqueur traditionally consumed as a digestive and now also popular as a festive drink, served either sipped or over ice. This liqueur has gained popularity and is currently a Protected Geographical Indication (PGI). There is also a festival-competition in Sant Coloma de Farners, a brotherhood promoting its knowledge, and several books, including: The secrets of ratafia, published by Farell Editors written by agricultural engineer Pep Escudero Rivas, now in its second edition.