This follows on from my question Is it safe to make mylk/milk from rice? which I realise was trying to ask two questions (if not three...)
I notice that the rice mylk I buy has a wonderful sweet taste, without the aftertaste of cane or beet sugar.
I have tried making rice mylk myself by blending soaked rice, and it has no sweetness (and tastes chalky).
It seems that the manufacturers of rice milk are using a clever fermentation process to break the rice starch down to natural sugars, as the Japanese have traditionally done when making amazake.
Is there any way I can achieve this myself? I don't want to add any kind of sweetening ingredients.