Along with the increasing need for functional ingredients, research on functional polysaccharides such as inulin continous to be explored from local plants. This study aimed to develop a method to obtain a high yield of Beneng tuber's inulin by extracting inulin with varying concentrations of ethanol (30 %, 40 %, 50 %, and 96 %), determining inulin content, and elucidating the structure. Moreover, the resulting inulin was applied in yogurt making. The study found that the highest yield of inulin was obtained at 50 % ethanol concentration, by 19.641 %, with solubility at 100 °C of 32.355 %, moisture content of 8.521 %, purity of 66.205 %, and reducing sugar content of 0.698 ppm. The structure analysis by FTIR confirmed the presence of an inulin-type fructan that is the same as commercial inulin. The XRD diffractograms showed diffraction peaks characteristic of 29 % crystallinity. The inulin was applied to yogurt resulting in the highest viability of lactic acid bacteria (3.05 × 1010 CFU/mL) by adding 7 % inulin. The organoleptic properties of treatment with 7 % inulin have the best result for all parameters with pH of 4, protein 3.79 %, fat 2.31 %, water 87.06 %, carbohydrate 6.23 %, and ash 0.71 %