The phrase 泥だんご, reading dorodango, is derived from
- 泥 (doro どろ) literally "mud" in Japanese
- だんご (dango) a type of round dumpling created from pressed rice flour.
Making the basic dorodango is a traditional pastime for school children, somewhat like English conkers.
More recently the process has been refined into the art of the hikaru ("shining") dorodango (光る泥だんご), which has a glossy surface. Several different techniques can be used. Across all methods, a core of the ball is made of basic mud, which has been carefully shaped by hand to be as round as possible. This core is left to dry, and then methodically and carefully dusted with finely sifted soil to create a crust several millimeters thick around the core. This step may be repeated several times, with finer and finer grains of dirt in order create a smooth and shiny surface. A cloth then may be used to gently polish the surface. The dorodango, once completed, may look like a polished stone sphere, but it is still very fragile. The process requires several hours and careful focus so as not to break the ball.
In the episode "End with a Bang" (Episode 113) of the Discovery series "MythBusters" that first aired on November 12, 2008, hosts Adam Savage and Jamie Hyneman investigated the truth behind everyday sayings. They used the dorodango technique to create dung spheres in order to bust the myth that one "can't polish a turd". Using a glossmeter, they measured gloss levels substantially higher than the value of 70 gloss units which is considered "high gloss". Savage's 106 gloss unit dorodango used an ostrich's feces, while Hyneman's 183 gloss unit specimen used a lion's feces. They therefore deemed the myth "busted".
- Bolton, T. Create hikaru dorodango. Retrieved from http://www.dorodango.com/create.html on February 19, 2013.
- Kayo, F. (2002). Dorodango: Shining mud ball. Retrieved from http://www.kyokyo-u.ac.jp/youkyou/4/english4.htm on February 2, 2013.
- "MythBusters Idioms Special". MythBusters. Season 6. Episode 113. 2008-11-12. http://dsc.discovery.com/tv-shows/mythbusters/videos/polishing-a-turd-minimyth.htm.
- "Shiny Mud Balls: Kyoto Professor Taps into the Essence of Play"
- Illustrated step-by-step guide to making Hikaru Dorodango
- Dorodango: Shining Mud Ball
- dorodango.com A gallery of marble-like Dorodango, and instructions for creating dorodango
- "Shiny Balls of Mud" -(William Gibson, TATE Magazine)