Food is a science, as well as an art, thus the topic gets attention during this year’s Philadelphia Science Festival, starting Friday through April 29. Among the highlights is a rare public appearance by legendary local chef Shola Olunloyo, wh*o will do a chemistry lab-meets-kitchen demo/discussion, “Extraction: Food and Flavor,” 7 p.m. Tuesday at World Cafe Live in West Philly ($25). “All Things Fermented: The Science of Beer and Cheese” is the topic for a tasting and discussion, 3:30 p.m. April 28 at Triumph Brewing in Old City ($50, 21-plus). And find out the answer to that eternal food question — Does the five-second rule matter? — when the University City Science Center and the Monell Center take on food safety “From Farm to Fork: Dangerous Foods — Facts, Fears and Foibles,” 6:30 p.m. Wednesday at Fairmount restaurant Rembrandt’s (free). Way more events and details at www.philasciencefestival.org.