Every winter and spring for the last 10 years, Philip Harper reckons he has had no more than a few nights of uninterrupted sleep, but he's more than willing to sacrifice some shut-eye in pursuit of the perfect glass of sake.

The only foreign brewer of Japan's unique nihonshu, Harper has learned his trade at the traditionally run Ume no Yado brewery in Shinjo, Nara Prefecture. But, despite his 10 years in the business, he's still got another decade to go before becoming a master brewer, and from next year he will be continuing his education at another brewery.

Still, he readily accepts that he has an awful lot more to learn.

"When I joined, the master brewer told me it takes 10 years to have any idea what's going on, and 20 years before you really grasp it," he says. "I've played the role of master brewer for a few batches a year for the last few seasons, so I can make sake [in terms of someone with 10 years' experience]. All the best brewers, though, are still studying like mad, however many decades they have under their belts -- and they'll all tell you that in sake-brewing, 'Maitoshi ichinensei [Every year is your first year].' "

Harper, 35, grew up in Cornwall, southwest England, and studied English and German literature at Oxford before arriving in Osaka in 1988 as an English-language teacher on the JET program.

Introduced to sake at a party a few months later, he admits it wasn't love at first sip ("It was just cheap, hot plonk"), but a more knowledgeable friend later handed him a better brew and he was hooked.

After joining a sake-tasting club, he visited breweries and sampled some of the output of the 1,700-odd producers in Japan. He has also hand-planted a rice paddy "borrowed" from an amused farmer, and handed the harvest over to a brewer to make into nihonshu.

"Our rice was not -- to say the least -- of the highest quality, but the brewer somehow contrived to turn it into a toothsome sake," he says.

In 1990, Harper began working part-time in a sake bar where he had previously spent so much of his salary. From there, it was a natural progression to his interest in the production process and history of the drink. Then, the following year, he talked Ume no Yado into giving him an apprenticeship.

Even though he had seen a brewery in action before, he was not prepared for the hard labor involved.

"The rigors of that first winter were beyond anything I had imagined," he says. "The work environment, the long days and the punishing physical work, plus the enormous amount of information to be absorbed and the mentally and physically testing nature of hand-brewing, all combined to reduce me to a rambling zombie."

The toll was such that he even ended up in the freezing local river one evening after managing to fall asleep on his bicycle while returning to the brewery for the night's session.

Tetsuo Ishihara, the toji (master brewer) under whom Harper first studied, admits that he initially had misgivings about the Englishman joining the firm. He also assumed Harper would throw in the towel after his first season of long days and back-breaking work.

Instead, after 10 years, he has not only persevered but has also become something of a sake celebrity, appearing on television and in newspapers and magazines, and lecturing on sake in fluent Japanese.

The working days in the November to March brewing season don't get any shorter, though. Harper and the rest of the brewery staff start at 6 a.m., and share a communal breakfast an hour later and dinner at 5:30 p.m. A final 45-minute stint from 7 p.m. is spent in the culture room for the koji, the rice mold that is combined with yeast and water to produce sake.

Since Harper is in charge of ensuring that the tricky koji is in good health, he spends virtually every night in the brewery, usually interrupting his sleep three times to check on its progress.

While it is ubiquitous in Japan, sake has not traveled all that well. This, however, is something Harper hopes to rectify -- partly through his book "The Insider's Guide to Sake" -- and he has no worries about the non-Japanese palate needing to be "educated."

"Booze is an international language," he says. "When I visit friends, I always take a few bottles with me. People have different favorites, but I have discovered that the friends who drink fine wine on a regular basis always go for what I consider the finest sake in the bunch."