Cooking chickens or other meats in a bamboo stem(which is a larger sized and different species of bamboo actually) is nearly almost easier. It is like putting prepared and marinated meat in a small pot. But cooking rice in a long and narrow bamboo stem is entirely a different kettle of fish if the phrase is appropriate here.
Some tips on making lemang. Lemang is glutinous rice or ordinary non-glutinous cooked in smaller and narrower bamboo stems.
Banana stem - get ready one stem of bananas for the bamboos so that they won't slip. Place this on the ground to get the correct angle for the bamboo stems against the fire.
A good metal plate like the one in the photo will keep the temperature even
Make sure that you fill the bamboo up till only 2/3rds and then top up with enough santan until the top like this: Note that banana leaves are not used when I cook the glutinous rice in this way. I have been told that this method will keep the rice fresh for a longer period.
The bamboos should be "stopped" at the top by crushed tapioca leaves or banana leaves which will add more fragrance to the lemang.