Rice drinks are made through an entirely natural process:
The rice is cleaned and milled and then left to soak in hot water. The fermentation process is the next step. Enzymes are added to get this process started. The product achieved after fermentation is the rice drink. Sunflower oil and a pinch of salt are added to give the rice drinks a slightly fuller flavour and mouth feel. Calcium and vitamins are also added to the enriched versions.
The rice starch transforms (hydrolyzes) during the fermentation process and natural sugars are formed: glucose, maltose and maltodextrin. This fermentation is an entirely natural process, which we could also call predigestion, because it is similar to how we process starch in our digestive systems.