HADONG JOURNALIn South Korea , Drinks Are on the Maple TreePark Jin - Hee for the International Herald TribuneDrinking sap from the maple tree known as gorosoe has long been a springtime ritual in the rugged hills in southern Korea . SIGN IN TO E - MAILPRINTREPRINTSSHAREBy CHOE SANG - HUNPublished : March 5 , 2009 HADONG , South Korea — At this time of year , when frogs begin stirring from their winter sleep and woodpeckers drill for newly active insects , villagers climb the hills around here to collect a treasured elixir : sap from the maple tree known as gorosoe . Enlarge This ImagePark Jin - Hee for The International Herald TribuneVillagers insert plastic spouts in the trees , and tubes carry the sap downhill . The sap has become popular in cities like Seoul . The New York TimesEvery year , Hadong produces 317 , 000 gallons of sap . “ It ’ s important to have the right weather , ” said Park Jeom - sik , 56 , toting plastic tubs up a moss - covered slope . “ The temperature should drop below freezing at night and then rise to a warm , bright , windless day . If it ’ s rainy , windy or cloudy , the trees won ’ t give . ” For centuries , southern Korean villagers like Mr . Park have been tapping the gorosoe , or “ tree good for the bones . ” Unlike North Americans who collect maple sap to boil down into syrup , Korean villagers and their growing number of customers prefer the sap itself , which they credit with a wide range of health benefits . In this they are not alone . Some people in Japan and northern China drink maple sap , and birch sap has its fans in Russia and other parts of northern Europe . But no one surpasses southern Koreans in their enthusiasm for maple sap , which they can consume in prodigious quantities . “ The right way is to drink an entire mal ” — 20 liters , or about 5 gallons — “ at once , ” said Yeo Manyong , a 72 - year - old farmer in Hadong . “ That ’ s what we do . And that ’ s what gorosoe lovers from the outside do when they visit our village . ” But how can you drink the equivalent of more than 50 beer cans of sap at one go ? “ You and your family or friends get yourselves a room with a heated floor , ” Mr . Yeo said , taking a break under a maple tree in Hadong , 180 miles south of Seoul . “ You keep drinking while , let ’ s say , playing cards . Salty snacks like dried fish help because they make you thirsty . The idea is to sweat out all the bad stuff and replace it with sap . ” Drinking gorosoe has long been a springtime ritual for villagers in these rugged hills , for whom the rising of the sap in the maples is the first sign of the new season . Some villagers even use the sap , which tastes like vaguely sweet , weak green tea , in place of water in cooking . In the past decade , thanks in part to the bottling industry and marketing campaigns by local governments , gorosoe sap has become popular with urban dwellers as well . “ I send most of my sap to Seoul , ” said Mr . Park , who harvests 5 , 000 liters , or 1 , 320 gallons , of sap in a good year . Koreans may have been drinking sap as early as a millennium ago , historians say . According to one popular legend , Doseon , a ninth - century Buddhist monk , achieved enlightenment after months of meditating cross - legged under a maple tree near here . When he finally tried to get up , his stiffened legs would not work . The sap from the tree fixed the problem . Hence the name ’ s meaning it is good for the bones . Mr . Yeo said that villagers used to make a V - shaped incision in the tree and insert a large bamboo leaf to run the sap into wooden or earthenware tubs . Then they would carry away the sap - filled tubs on their backs . Today , villagers usually drill holes in the trees and insert plastic spouts . A maze of plastic tubing carries the sap to holding tanks downhill . Every year , Hadong produces 317 , 000 gallons of sap , which fetches between $ 6 and $ 7 a gallon . Although most sap harvesters here are tea or persimmon farmers who gather sap on the side for extra income , some enterprising villagers have begun planting thousands of maple trees as a primary business venture . Some rural governments host gorosoe festivals for tourists , with activities that include sap - drinking contests and rituals venerating mountain spirits . A popular place for drinking sap is public bath houses , where customers take the tonic while relaxing on heated floors . Promotional pamphlets advertise the sap ’ s purported benefits : it is good , they say , for everything from stomachaches to high blood pressure and diabetes . Lee Jae - eung , a naval officer attending the gorosoe festival on Koje , an island east of Hadong , with his two daughters , said he liked the sap because “ it soothes my stomach after a hangover . ” Most of these claims have yet to be substantiated , said Kang Ha - young , a researcher at the Korea Forest Research Institute . “ But one thing we have found is that the sap is rich in minerals , such as calcium , and is good , for example , for people with osteoporosis , ” he said . “ Somehow , our ancestors knew what they were doing when they named it . ” The seesawing temperatures are needed to collect gorosoe because they build pressure inside the tree , which causes the sap to flow more easily when the trunk is punctured , preferably on its sunny side . Now that sap - gathering is becoming more commercial , some environmentalists have criticized tree tapping as “ cruel . ” “ I oppose boring holes in a tree and drinking its sap , ” said Kim Jeong - yon , 46 , a tourist visiting Koje . Mr . Kang , the researcher , says careful tapping is harmless . To ensure this , the national forest authorities recently began requiring licenses for sap collectors and regulating the number of holes they can bore into each tree . Gorosoe farmers , who were doing a brisk business selling sap to visitors from makeshift stands , acknowledged the need for restraint . “ The trees donate their blood to us , ” said Yang Heung - do , 51 . “ If you donate too much blood , you get weak . So we drill only one to three holes per tree , depending on its size . ”