Onlce Levain is a fermented bread cafe at the end of a narrow alley in Ikseon-dong, Seoul. It bakes cream cheese sweet pumpkin ciabatta, basil cheese tomato ciabatta, and campagne every day, and ferments its own kombucha. The shop is found by following the bread placed along the alley, and drip coffee and bread can be eaten together in the store. The store is small.