Disclosed is a fermented mousse cake using the yeast natural yeast fermentation species that can be improved to include a yeast natural yeast fermented with yeast and having a taste better than before. The method for producing a fermented mousse cake using a vegetable lactic gentle yeast natural yeast fermentation product according to the present invention is a method for fermenting a fermented mousse cake by mixing yeast, barley powder and water at a first room temperature, adding a predetermined amount of barley powder and water to the first fermentation product Adding a predetermined amount of barley powder and water to the secondary fermentation product and further subjecting the fermented product to a third low-temperature fermentation step to produce a predetermined amount of yeast fermented yeast； The yeast fermentation seed dough of the yeast natural yeast fermentation dough is foamed and mixed with the egg yolk by mixing the barley powder, sugar, starch syrup, milk and yeast fermentation seeds, And the mixture was mixed with the yeast dough. The butter was dissolved in a hot water bath and mixed with milk, edible oil, and rum in a kneader of the yeast natural yeast fermentation seed. Then, the Yeast Yeast Yeast Fermentation Species Pouring dough and steaming for a certain time to make a steam cake sheet； Strawberry, gelatin, sugar, strawberry jam, nourishing barley powder dough, yeast natural yeast fermented seeds, strawberry milk, water, boiled, cooled at room temperature, then raised the whipped cream, mixed with lactic acid bacteria to make a cream .누룩이 발효된 누룩천연효모가 포함되도록 하고, 종래보다 식감도 부드러운 맛을 갖도록 개선될 수 있는 누룩천연효모 발효종을 이용한 발효무스케익 제조방법 및 이를 이용하여 제조된 발효무스케익이 개시된다. 본 발명에 따른 식물성 유산누룩천연효모 발효종을 이용한 발효무스케익 제조방법은, 누룩, 보리분말, 물을 혼합하여 1차 상온에서 발효시키고, 상기 1차 발효물에 일정량의 보리분말 및 물을 추가적으로 넣고 2차 저온 발효하고, 상기 2차 발효물에 일정량의 보리분말 및 물을 추가적으로 넣고 3차 저온 발효하는 공정을 통하여 일정량의 누룩천연효모 발효종을 만드는 단계； 보리분말, 설탕, 물엿, 우유, 누룩천연효모 발효종을 혼합하여 저온 발효시켜 누룩천연효모 발효종 반죽을 만든후, 상기 누룩천연효모 발효종 반죽에 계란의 황란을 거품내어 혼합
