Japan; adapted from Chinese chili oil; S&B taberu rayu popularization 2009 created new category
Rayu (spicy sesame oil) is Japan's most widely used chili-infused condiment—sesame oil infused with dried red chili, garlic, and sometimes additional aromatics (sesame seeds, negi, ginger), used as a finishing condiment across Japanese-Chinese hybrid dishes, gyoza, ramen, and cold tofu. The Japanese version is distinctly different from Chinese chili oil: S&B Brand's taberu rayu ('eating spicy oil') popularized a new category of rayu with substantial solid content (crunchy garlic and chili pieces suspended in the oil rather than filtered out) that became a sensation in 2009. This eating-format rayu is spooned directly over rice, mixed into pasta, and applied to poached or fried eggs. The base sesame oil is typically toasted (roasted) sesame oil with a rich, nutty fragrance. The chili can be ichimi, dried hontaka, or Korean-style gochugaru (adding a richer chili flavor). Homemade rayu can be calibrated for heat level and texture. Rayu's oil base means a small amount provides significant flavor—the capsaicin is dissolved into the oil, giving sustained heat rather than acute spiciness. Standard application: several drops drizzled over gyoza dipping sauce, a small spoon over cold silken tofu, or mixed into ramen bowl at the table.
Rich toasted sesame; sustained capsaicin heat; garlic and chili fragrance; solid-version adds crunch
{"Sesame oil (toasted for maximum fragrance) is the base—not neutral oil","Traditional strained rayu versus taberu rayu (solid content retained) represent two product categories","S&B taberu rayu 2009 popularization changed Japanese condiment culture with the solid-content format","Small amounts provide sustained heat from capsaicin dissolved in oil—use sparingly","Homemade: heat sesame oil to just-smoking, pour over chili and garlic, steep and strain or leave solids"}
{"Garlic-forward rayu: fry thin garlic slices until golden, strain oil, use oil (strain version)","Taberu rayu: pour 180°C sesame oil over mix of chili flakes, garlic, sesame seeds, dried shrimp","A few drops of rayu over cold tofu with soy sauce and grated ginger is a quick elegant dish","Store homemade rayu in the refrigerator—the solid content can grow bacteria at room temperature"}
{"Using neutral oil instead of toasted sesame—loses the characteristic rich sesame fragrance","Applying too much—rayu's concentrated oil carries flavor and heat that overpowers quickly","Heating sesame oil beyond smoking point which produces bitter burnt sesame notes","Expecting rayu to substitute for more assertive Chinese chili oil—flavors differ significantly"}
Tim Anderson — JapanEasy; Japanese condiment culture documentation