Dotori guksu are Korean noodles made from acorn flour or starch, salt, and a combination of grain-based flour (usually buckwheat or wheat).
Dotori guksu may be made from acorns collected from red or white oak species and each oak species gives a distinct flavour. Ingredient labels do not list from which type of tree acorns are gathered, most likely due to the large number of oak species and increasing oak hybridization (especially among white oak varieties), which makes it difficult to recognise and document each type of species.
Read more about Dotori Guksu: Origins