Dear Alice,

You know how when you order nihonshū (Japanese sake) in a bar or restaurant, and your server brings a glass to the table and sets it inside another vessel? And then he or she picks up a bottle of sake and pours until the sake spills over the top of the glass and into the vessel below?

My friends and I have always wondered why that is done. Also, what is the proper way to drink this? Are you supposed to first finish off the sake in the glass and then tip the contents of the underlying vessel into the glass? Or drink the overflow straight from the vessel itself?

Ross W., Tokyo

Dear Ross,

I'm so glad you raised this question; I'm brimming with curiosity. The set-up I've seen most often is a glass placed inside a square wooden box, which I know is called a masu, but sometimes the glass comes atop a dish or saucer. Either way, the etiquette has always escaped me. And it's not just the question of which do you drink first; how the heck do you even start when the glass is too full to pick up?

To get some answers, I put in a call to the Sake Service Institute in Tokyo, figuring that with a name like that, it ought to know a thing or two about serving sake. It turns out SSI is the organization that trains and certifies kikisake-shi, which is like a sommelier, but for sake instead of wine. More than 30,000 men and women have been certified since the program was launched in 1990, including some 500 people outside of Japan. A kikisake-shi is qualified to advise on proper storage and handling, as well as food pairings and just about anything else you'd like to know about Japanese rice wine.

I sat down with SSI executive director Haruyuki Hioki, who explained that the overflow style of pouring — to the extent that it has a name — is generally referred to as "sosogi-koboshi." That's a noun cobbled together from the verbs "sosogu" (to pour) and "kobosu" (to spill over). It's also sometimes called "mokkiri sake," borrowed from a more general term for a single but generous serving of food or drink.

There's no special meaning or long tradition behind sosogi-koboshi, Hioki told me. It first became popular during the immediate postwar period, and was originally seen only in the drinking joints that sprang up under railway tracks and around stations in working-class neighborhoods during Japan's period of high-economic growth. Gradually, and particularly in the last decade, the practice was picked up by a wider range of bars and restaurants, spreading with the increased popularity of drinking sake chilled rather than heated or at room temperature.

"Filling a glass until it overflows is just a form of service," Hioki explained. "It's a gesture that makes the customer feel good because they think they've been given something extra."

But not everyone is pleased to be served this way. Many customers, and particularly women, consider it unhygienic, something I discovered through a quick Internet search.

"I'll tell you why I don't like it: the masu is unclean," one woman wrote on her blog. "I could understand if they used a new one every time, but re-using a container made of wood? There's no way to get those four corners clean! And I don't trust the bottom of the glass. It was just sitting on some shelf, right? Do you really expect me to drink sake that has been in contact with the filthy bottom of a glass? The whole concept is revolting."

That is not just the ranting of a hygiene freak with an advanced case of keppekishō (an irrational fear of dirt and germs); the sanitation concern is very real, Hioki insists. "There's no law against sosogi-koboshi, at least not yet, but in our courses we specifically advise against it," he says. "There are just too many risks."

And keep in mind, he said, that the masu was never intended for drinking: "Except at celebrations, when a barrel of sake is broken open and guests are presented with a new masu to drink from and take home as a souvenir, the masu shouldn't be used this way. It's very hard to drink from a square without spilling."

This brings us back nicely to your question about "the proper way" way to drink sake served to overflow.

"There's no specific etiquette associated with this," Hioki told me. "It's not anything refined and you'd never see it done in a formal setting. But if I had to offer advice, I'd suggest drinking down the glass until you've got room to pour the overflow into the glass. Then set the masu or dish aside."

My own observation, however, is that every drinker tackles the problem differently. I've seen people simply pick up the glass, knowing the vessel below will catch any spills. Others lower their head and take a no-hands sip to bring the level in the glass under control. Some drink the glass down completely before turning to the overflow, while others tip it into the glass as soon as there is space. And while confirmed barflies will swear you're supposed to drink from the straight edge of the masu, with the mark facing toward you, I've heard others say drinking from the corner is the only way to go. My conclusion is there's no need to worry about manners; just have fun and revel in the abundance.

Except — and I really hate to throw yet another wet blanket on this party —there's no guarantee that you've actually received anything to revel about. And therein lies a second problem with sosogi-koboshi, and sake service in general.

"A single measure of sake, which is called 'ichigō,' should be 180 ml," Hioki explained. "But many bars and restaurants serve significantly less, even when poured to overflow."

Sometimes the discrepancy is deliberate; more often, servers haven't checked the volume of the many different glasses, jugs and decanters used to suit the season or food served.

"Either way, it is fraud," Hioki asserted. "The very basis of good customer service is honest communication about portions and pricing."

Learn more about kikisake-shi at