Sesame cultivation in Japan traces to the Yayoi period (300 BCE – 300 CE); sesame oil pressing is documented from the Heian period; the specific tradition of deep-roasting before pressing to maximise aromatic compound development is a Japanese refinement of Chinese sesame oil production technique; Kadoya, the leading Japanese sesame oil producer, was established in 1858 and maintains the traditional double-press method
Japanese roasted sesame oil (goma-abura — 胡麻油) is categorically different from light sesame oil used in Chinese stir-frying or the pale varieties in Western kitchens — it is pressed from deeply toasted white sesame seeds, producing an intensely fragrant dark amber oil with pyrazine and Maillard aromatic compounds that define its unique flavour. The production: white sesame seeds are carefully toasted to a specific colour (deep golden, past the standard pale toasting of most sesame products) before cold-pressing; the high-temperature roasting before pressing generates the aromatic compound profile (methyl pyrazine, trimethylpyrazine, and 2-furanmethanol) that gives Japanese sesame oil its nutty-toasted character. In Japanese cuisine, goma-abura is used exclusively as a finishing oil rather than a cooking oil — its aromatic compounds are heat-volatile and the flavour is destroyed by high-temperature cooking. Applications: added to ramen bowls (a few drops across the surface of the hot broth), used in dressings for aemono and sunomono, drizzled over cold noodle preparations, and as the stir-fry medium for kinpira at moderate temperature. The distinction in Japanese cooking between goma-abura (dark, aromatic, finishing) and joma-abura (clear, refined, neutral cooking oil) must be understood for correct applications.
Dark roasted sesame oil is for finishing, not cooking at high heat; the fragrant compounds are volatile — add to hot dishes immediately before serving; a small amount (drops, not tablespoons) provides the aromatic impact; quality indicator: the oil should smell intensely nutty-toasted, not stale or fishy; store in a dark cool location — light degrades the aromatic compounds rapidly.
The ramen sesame oil application: pour 3–5 drops over the bowl at service just before the customer receives it — the heat of the broth activates the aromatic compounds, releasing a perfume of toasted sesame that is the olfactory announcement of the ramen; the best sesame oil brands in Japanese cooking are Kadoya and Maruhon — both use traditional double-press methods; for storage, dark glass bottles extend shelf life significantly; the 'life' of opened sesame oil is 3 months at room temperature — after this, oxidation creates off-flavours.
Using sesame oil as a cooking oil at high heat (destroys aromatic compounds within 30 seconds); adding sesame oil too early and cooking it (loses the entire point of the ingredient); confusing dark roasted sesame oil with light/untoasted sesame oil (entirely different flavour register); over-using (a few drops, not a tablespoon — the intensity is extreme).
Tsuji, Shizuo — Japanese Cooking: A Simple Art; Shimbo, Hiroko — The Japanese Kitchen