Tape ketan [tah-phe k'tan] is a fermented sticky [glutinous] rice prepared in Indonesian [ketan means glutinous rice]. Tape has a sweet taste with amounts of alcohol, somewhat resembling Japanese sake in essence. The amount of alcohol in tape is mostly dependent on the fermentation process or duration, but alcohol may range between 6 - 10 %. The sweet taste with amounts of spirit of alcohol of tape are the main features in tape's taste sensation and aroma.
Tape ketan is prepared by cooking glutinous rice with water, cooling and inoculating the cooled rice with crushed ragi yeast cake. The amount of ragi added is about 1 yeast cake per 1 to 3 cups of uncooked rice. The crushed ragi powder is stirred in the cooled rice-mix, and then the ingredients are placed in a covered bowl and fermented at room temperature [about 30° C] for 1 - 3 days. Traditionally, the rice is usually coloured green with green plant extract, but today, artificial food colouring has taken the place of natural plant extracts. Although there is a non-coloured variety of tape made from white glutinous rice. There is also Tape ketan-hitam, prepared with black glutinous rice. The preparation is the same as for tape ketan, substituting white glutinous-rice with black glutinous rice, ketan-hitam [hitam means black in Indonesian].