Japan — rayu introduced from Chinese culture; domesticated as gyoza condiment from 1950s; taberu rayu trend launched by S&B Foods 2009; artisan eating oil market expansion from 2010–present
Rayu (辣油, literally 'spicy oil') is Japan's primary chili oil condiment — a sesame oil base infused with dried togarashi peppers, aromatics, and in its most refined forms, dried seafood and vegetables. The category divides into two distinct products: traditional thin rayu (for gyoza dipping, ramen finishing, cold tofu) and the post-2009 revolution of taberu rayu ('eating oil' or 'eating chili oil'), a semi-solid textured condiment popularised by S&B Foods' La-Yu with Crunchy Fried Garlic and Onion product that sparked a national trend. Taberu rayu contains fried garlic, onion, sesame seeds, and occasionally dried seafood in a dense paste that provides both heat and substantial texture — it is eaten directly by the spoonful on white rice, creating a complete quick meal. The artisan rayu market has exploded since 2009: roasted black bean rayu; dried scallop and chili; spicy miso-based versions; dried sakura shrimp versions; various degrees of heat from mild Shishito togarashi to intense Korean gochugaru base. Professional rayu production: infuse sesame oil and neutral oil blend with whole dried togarashi at 180°C for 3–5 minutes (the oil should sizzle vigorously around the peppers), strain, then re-infuse with aromatic additions at 130°C. The temperature management is critical: too hot destroys the sesame oil's aroma; too cool fails to extract capsaicin efficiently. Mayu (black garlic oil) — a related product where garlic is charred to near-black and infused into oil — is the Kumamoto ramen (Kogashi mayu) signature.
Traditional thin rayu delivers a clean, sesame-aromatic heat; taberu rayu adds textural dimension through fried garlic and onion crisp — the combination of chili heat, sesame depth, and fried aromatic crunch creates a complete flavour experience suitable for direct rice service
{"Rayu: traditional thin sesame-chili oil for dipping and finishing; taberu rayu: textured eating oil with fried ingredients","Taberu rayu revolution: S&B 2009 product created a national trend for texture-heavy eating chili oil","Production: infuse sesame oil + neutral oil at 180°C with dried togarashi for 3–5 minutes","Temperature management: 180°C for capsaicin extraction; not above to preserve sesame oil aroma","Taberu rayu components: fried garlic, fried onion, sesame seeds, optional dried seafood","Mayu (black garlic oil): charred garlic infused in oil — Kumamoto Kogashi mayu ramen signature","Artisan rayu varieties: dried scallop, sakura shrimp, roasted black bean, spicy miso","Thin rayu application: gyoza dipping, ramen finishing, cold tofu, kimchi enhancement","Taberu rayu on rice: the direct eating-oil-on-rice application — a complete quick meal created by the trend","Heat calibration: hontaka for traditional Japanese heat level; gochugaru for Korean-influenced versions"}
{"House thin rayu: 3:1 sesame to neutral oil, infuse hontaka at 175°C 4 minutes, strain, cool — excellent quality in 15 minutes","Taberu rayu upgrade: fry garlic slices at 130°C until golden, drain, add to cooled rayu base with toasted sesame and dried sakura ebi","Mayu for ramen: blacken 2 heads garlic in a dry pan until completely charred, blend with sesame oil — 1 teaspoon drops into Kumamoto-style ramen","Cold tofu with thin rayu: arrange cubed silken tofu, pool of rayu, spring onion, bonito — rayu on cold tofu activates immediately on the warm surface","Korean gochugaru base rayu: substitute 30% of hontaka with gochugaru for a sweeter, smokier, less sharp heat profile"}
{"Heating sesame oil above 180°C — burns the sesame oil's aroma into a bitter, harsh character","Under-heating oil for capsaicin extraction — rayu at 130°C is insufficiently hot for full capsaicin extraction","Adding fresh garlic to hot rayu oil — fresh garlic burns immediately; must be pre-fried to golden before adding","Using rayu in place of taberu rayu in eating applications — thin rayu lacks the texture that defines the eating experience","Storing rayu in warm conditions — the chili infusion accelerates at warm temperatures; store refrigerated"}
Tsuji Shizuo — Japanese Cooking: A Simple Art; S&B Foods — Rayu Product Culture Documentation