[vintermann]

You definitively can't get kvass on your average Kiwi. I can't even get it my local Spar or Mega. But there are always odd exceptions (my local Mega pushes mochi heavily for some weird reason).

Immigrant shops are your best bet, it's true.

[older]

My local Spar has "east european foods" shelf. There's no kvas, but a lot of other good stuff though.