I think I'm going to try it first with citrus, but then, I'm going to try it with coffee. That means, of course, I shall have to select the coffee beans . . .
There's a potato vodka make in Idaho that I very much favor;
Koenig Vodka. But given Washington state's idiotic decision to abandon the state liquor stores, I suspect I won't be able to find it locally, and the single online retailer isn't carrying the plain Koenig vodka anymore.
My fallback is another Idaho potato vodka;
Glacier vodka.
It's a little sweeter, but I think it would work especially well as a base for coffee infused vodka.