unsophisticated palate; inability to discern good and bad flavors
Describes someone who cannot tell the difference between good and bad taste, or who has no refined sense of flavor. Often used self-deprecatingly or to tease someone who likes cheap food.
He has an unsophisticated palate, so he can't tell even if he drinks expensive wine.
I think I have no sense of taste, so I can't critique cooking.
Compound of 味 (taste) and 音痴 (tone-deafness). The word 音痴 is extended metaphorically to mean a lack of ability in a certain area, here taste.