also be used for chilled sake. Traditionally one does not pour one's own drink, which is known as (), but instead members of a party pour for each other, which is known as (). This has relaxed in recent years but is generally observed on more formal occasions, such as business meals, and is still often observed for the first drink. Another traditional cup is the masu, a box usually made of hinoki or sugi, which was originally used for measuring rice. The holds exactly one gō, , so the sake is served by filling the to the brim; this is done for chilled or room temperature sake. In some Japanese restaurants, as a show of generosity, the server may put a glass inside the or put the on a saucer and pour until sake overflows and fills both containers. Sake is traditionally served in units of , and this is still common, but other sizes are sometimes also available. Saucer-like cups called are also used, most commonly at weddings and other ceremonial occasions, such as the start of the year or the beginning of a kaiseki meal. In cheap bars, sake is often served at room temperature in glass tumblers and called (). In more modern restaurants, wine glasses are also used, and recently footed glasses made specifically for premium sake have also come into use. Traditionally sake is heated immediately before serving, but today restaurants may buy sake in boxes that can be heated in a specialized hot sake dispenser, thus allowing hot sake to be served immediately. However, this is detrimental to the flavor. There are also a variety of devices for heating sake and keeping it warm beyond the traditional . Aside from being served straight, sake can be used as a mixer for cocktails, such as tamagozake, saketinis, or nogasake. Outside of Japan, the sake bomb, the origins of which are unclear, has become a popular drink in bars and Asia-themed karaoke clubs. The Japanese Sake Association encourages people to drink chaser water for their health, and the water is called Yawaragi-mizu. Seasonality Because the cooler temperatures make it more difficult for bacteria to grow, sake brewing traditionally took place mainly in winter, and this was especially true from 1673 during the Edo period until the early 20th century during the Showa era. While it can now be brewed year-round, seasonality is still associated with