In 1999, Ferran Adrià and his team were designing a new menu for the Hacienda Benazuza hotel in Seville, made up of elBulli's past dishes. They took the opportunity to record the date of each dish, and this simple act meant that it was easy to see when certain concepts and techniques had been introduced. That moment marked the beginning of the monumental task of cataloging every dish since 1987, which they consider to be the year they produced their first original recipe. This was chosen as recipe No. 1, and the last, dating from 2011, is recipe No. 1,846.