Like the wines, various types of sake should be drunk at their appropriate temperature. Kan, the warm sake, is one of the traditional ways: the drink is warmed in small porcelain bottles up to 35°–45°C, but the temperature must not rise above 50°C, because the delicate aroma will be lost. Some varieties like Namazake ("draft sake" - that's my favorite) are served cold at 8°–10°C, but they shouldn't be chilled below 5°C, because you cannot feel the taste anymore...
EXIF info:
Nikon D700
Lens: 24-70mm F/2.8G
Focal Length: 32mm
Aperture: F/4.5
Shutter Speed: 1/60s
ISO Sensitivity: ISO 1600