Most required instructions on how to eat them, sometimes with bare hands.
Food took on unexpected shapes, textures and temperatures as the chef used liquid nitrogen to produce vegetable or fruit foam, airy, ethereal reincarnations of solid food, combining seaweed and tea, or caviar with jellied apples.
His "bunuelo de llebre" is a small ball whose external surface is a chilled delicate pastry that conceals "hot liquid hare which you must bite into with your lips closed," enabling its caramel-like taste to explode inside your mouth.
The restaurant's average price of €270 ($388) per head — not including drinks, tax or tips — was another of its distinctive features.
The diner could boast more than a million reservation requests yearly at a place that seated just 50 and opened for dinner only, usually just six months a year.
The other six months were used by Adria to travel the world in search of ideas and then to conceive and painstakingly practice preparing dishes that have astounded gastronomy critics and dedicated foodies alike.
"El Bulli will be opening again, just not for reservations," said Adria at a farewell press conference in the rock garden outside his restaurant surrounded by dozens of colleagues, former and current.