Updated: Oct 31, 2019
Sake can be found at most establishments serving alcohol, especially at restaurants and drinking establishments such as izakaya and bars. There are also specialty sake bars that stock a wide range of sake from various regions.
Similar to wine, sake comes in a range of flavors that vary in complexity and nuance. At the most basic level, sake is described as either sweet (ama-kuchi) or dry (kara-kuchi). The sweetness of sake is often listed on the menu with a number value known as the sake meter value (nihonshudo). The scale goes from -15 (very sweet) to +15 (very dry).
Sake is also served at a variety of temperatures depending on the sake, season and individual taste. Generally speaking, most premium sake is best enjoyed chilled or at room temperature (especially the expensive ginjo and daiginjo), while cheaper and less flavorful sake holds up well when served hot (called atsukan) and can be very enjoyable especially during the cold winter months. When in doubt, consult the server for a recommendation.
At restaurants, the amount of sake is commonly sold in the traditional unit called go (合) which corresponds to about 180 ml, e.g. ichi-go (one go), ni-go (two go), etc. In addition, small bottles (300 ml) and larger bottles (720 ml) are often available. Sake is commonly served in small sake cups, a glass or a glass placed into a wooden box (masu). When drinking in groups, it is customary to serve one another, rather than just serving yourself. You should periodically check your friends' glasses, and replenish them before they get empty. Likewise, if someone serves you, you should hold up your glass towards the person and then take one sip before putting the glass down.