In the beginning, there was a sphere and a little bang: a bubble of liquid olive that burst in your mouth, a culinary innovation introduced in 2003 by chef Ferran Adria of the now-defunct El Bulli in Spain.

Then came the edible helium balloons made of green apple taffy, courtesy of American chef Grant Achatz. You popped them to inhale the gas, channel Bart Simpson and nibble their sweet skin.

Those balloons are still around, their phase in the timeline of molecular cuisine still yet to pass. And so is Achatz, now 51 and still going strong in his 20th year as head chef and owner of Alinea, the avant-garde restaurant in Chicago that pushes the boundaries of cooking by transforming ingredients into myriad shapes and textures. The dishes are often served with theatrics, such as painting a tabletop with desserts. Surprise is central to Achatz’s repertoire.