In Thailand, a few amounts of TSCs are used as handicraft making raw material, as material for filling pillowcase or as scrub cocoons for traditional remedy. The leftovers are used as fish food and fertilizer. Owing to its substantial quantity, low price and advantageous properties, it has the potential to be used as immobilizing material for ethanol industries. Therefore, in this study, thin-shell silk cocoons were used for the natural immobilization of yeast cells for ethanol production in repeated batch and continuous fermentations of blackstrap molasses. To the best of our knowledge, this is the first report of the use of silk cocoons for yeast cell immobilization