With the arrival of spring, it's time to look for crisp, refreshing, unoaked whites. One of the best sources of exciting new-wave whites is Galicia in north-west Spain. Here remote, little-known regions are demanding the limelight with their fine, indigenous white grapes. One of the most impressive is the godello grape. An ancient grape, which derives from Roman times, it was almost extinct here in the 1970s.