Udisha
Lemon or lime
Matcha and citrus simply sounds wrong. The sour and acidic flavour of lemon or lime will completely ruin the delicate and grassy flavour that matcha is famous for.
Dark roast coffee
While coffee matcha is quite famous, an espresso shot made out of dark roast coffee will end up making the drink bitter, completely overpowering the subtle notes of matcha.
Pungent spices
Matcha should never be mixed with heavy spices like garlic or cumin. This cannot be made like a traditional chai because matcha's flavour is distinct and unique which will clash with the strong flavours.
Artificial syrups
Matcha has a grassy, vegetal note and so when mixed with synthetic syrups that are extremely sweet, it will result in a mixture that retains none of the smoothness or umami depth of the powdered tea.