Japan — yomogi use in food documented from at least the Heian period; kusa mochi tradition associated with spring festivals (particularly Hinamatsuri, March 3); Akita's preserved aeku tradition of considerable antiquity
Yomogi (Artemisia princeps, Japanese mugwort) is one of Japan's most culturally significant food plants—simultaneously a spring herb, a medicinal plant, and a fundamental ingredient in several iconic wagashi forms. Its most celebrated culinary application is in kusa mochi (literally 'grass mochi') or yomogi mochi: glutinous rice pounded with blanched and finely pureed yomogi leaves, producing a striking pale green, intensely aromatic mochi with a distinctive earthy, herbal bitterness that complements sweet anko filling. The flavour of yomogi-infused mochi is unmistakably Japanese spring—a transient green bitterness that signals the first warmth, simultaneously herbal (thujone, cineole, flavonoid compounds) and comforting (the sweetness of mochi and anko). The medicinal tradition around yomogi is documented in Chinese and Japanese medical texts for over 2,000 years: moxa (moxibustion)—the burning of dried yomogi on acupuncture points—remains a cornerstone of traditional Chinese and Japanese medicine. Yomogi tea (yomogi-cha) is consumed as a digestive and general tonic. In food applications, yomogi must be blanched briefly in boiling water, shocked in ice, squeezed firmly to remove excess moisture, then puréed before combining with mochi or other bases. The blanching removes some of the sharper aromatic compounds while preserving the characteristic green colour and gentler herbal notes. Yomogi is also used in making kusamochi dumplings in Kyushu and is the fundamental ingredient in aeku (Akita Prefecture's preserved yomogi), a regional food tradition of considerable antiquity.
Yomogi mochi: earthy, slightly bitter herbal note from mugwort; glutinous rice sweetness; anko's sweet earthiness; the herbal bitterness is specifically celebrated as the taste of spring—a seasonal flavour rather than an unwanted attribute
{"Blanching and shocking: boil yomogi 60–90 seconds in heavily salted water until bright green; immediately transfer to ice water to fix colour and halt cooking","Moisture removal: squeeze blanched yomogi firmly multiple times to remove as much water as possible—excess moisture in yomogi purée creates soft, sticky mochi that won't hold shape","Purée texture: grind squeezed yomogi in a suribachi (mortar) until completely smooth and paste-like before incorporating into mochi—coarse yomogi creates uneven colour and texture distribution","Colour stability: the chlorophyll in blanched yomogi is reasonably stable in slightly acidic environments but will turn olive in alkaline conditions or under prolonged heat—use quickly after blending","Mochi incorporation: add yomogi purée to just-pounded mochi, folding vigorously—the natural stickiness of glutinous rice bonds with the yomogi paste to create an evenly coloured, cohesive dough","Harvest season: young yomogi shoots in early spring (March–April in most of Japan) have the most tender leaves and freshest flavour; summer yomogi is coarser and more aggressively bitter"}
{"Yomogi mochi with white anko (shiro-an): white bean anko (from white haricot beans) filled yomogi mochi creates a more delicate flavour pairing than the standard red adzuki anko—the mild sweetness of white anko allows the yomogi's herbal character to dominate","Preserved yomogi paste: blanch, squeeze, and purée a large batch of spring yomogi; freeze in ice cube trays—frozen yomogi paste maintains its flavour for 3 months for use beyond the fresh season","The foraging narrative: yomogi grows wild across Japan's mountain meadows and roadsides; a menu note specifying that the yomogi was hand-foraged from specific mountain slopes creates genuine provenance","Yomogi in savoury applications: add blanched and puréed yomogi to tempura batter for a striking green tempura variation; or incorporate into udon dough for a herbal, green spring noodle","Yomogi's medicinal context for guests: explaining that yomogi has been used in Japanese medicine for 2,000 years for its warming and digestive properties—that the same plant is both a medicine and a wagashi ingredient—is a compelling bridge between food and traditional health culture"}
{"Using old or summer-harvested yomogi—mature yomogi is significantly more bitter and less tender; spring shoots are the wagashi-quality standard","Insufficient moisture removal—wet yomogi purée produces sticky, shapeless mochi that won't hold through preparation and service","Blanching in unsalted water—salt sets the green colour (chlorophyll stabilisation) and removes more of the harsh volatile compounds; unsalted blanching produces a less vivid colour","Over-blanching—beyond 90 seconds, the yomogi begins to lose colour and aromatic character; the brief blanch should preserve the green and gentle aromatic compounds","Not pureeing completely before incorporation—coarse yomogi in mochi creates uneven green distribution with bitter patches of concentrated herb material"}
Japanese Farm Food — Nancy Singleton Hachisu; Japanese Confectionery — Tomoko Takebe