the temperature of the milk is very important. you boil the milk first (or microwave til boiling); then pour the boiling milk to another empty big cup, then back to the original pot-- repeat this process 10 times (must be 10 times). then pour the milk to the bowl with 1 tablespoon of ginger juice and 1 tablespoon of sugar. if you use a few drops of ginger juice it wouldn't work.
i hope you understand my confusing explanation!
I use normal milk. to make more ginger juice you have to use a big piece and grate it and then squeeze the juice out