I got back from Korea a couple weeks ago and was given this recipe from the concierge at the hotel.
I've read it over and over (correcting the English, etc.).
Through research I found the nooruk is actually "amylase emzyme" which can be purchased in some homebrew stores. How much to use is another question.
DONG DONG JU Recipe
Korean rice: 1KG
Yeast – 8 gm., any wine yeast will do for DDJ in Korea.
Nooruk - enzyme 200gm. - made with crushed wheat malt.
Clean water - 1.6 liter, I used filtered water
Method: (all equipment must be sanitized, hands included)
1) Wash 1KG of Korean rice and soak overnight.
2) Allow to drain for at least 2 hours prior to steaming.
3) Into the steamer for 1 hour of steam cooking.
4) After rice is well cooked, spread it onto a tray to cool to room temperature.
5) After it is cooled, add crushed Nooruk and yeast. (wear a disposable plastic glove, sprayed with Iodophor to mix thoroughly by hand).
6) Once thoroughly mixed, the rice is ready to be placed into a fermenter.
7) Add 1.6L of clean or bottled water into the mixture.
Basically what happens is the nooruk converts the steamed rice into sugar for fermentation. Nooruk is made with crushed wheat malt and water. It is a mold that occurs naturally with wheat malt.
Almost 2 hours after the mash is in the fermenter, all water is absorbed by the rice malt.
After 3 days stir the mash twice a day until it is ready to serve in 10 days.
For steps 5 and 6 I would probably just pour all the contents in a fermenter (a gallon jug, etc) and shake it all together.
DDJ should taste sweet and look a lot like tan colored skim milk.
"Dong" means "sh#t" in Korean. It refers to the rice particles floating in the brew. So technically. DDJ is unfiltered Makkolli (too many spellings for this brew).
One night I had 2 - 1,5 liter bottles of Makkolli then went out to the restaurant and ordered another bowl of DDJ.
I have not tried this yet, but if anyone has anything to add to the recipe or techniques I would appreciate it.