When it comes to grains, we are spoilt for choice. We believe a variety in our diet is good for us- Not only will it provide a range of nutrients but it will also help develop the gut biome. For years we have been eating idlis and sannas made of rice and fermented with either Black gram (Urad dal) or Toddy.
Today we made a change, we replaced the rice with Finger millet (Ragi) and Unhulled Buckwheat (50:50); both are nutritious cereals and rich in fibers and we fermented them for 14 hours with black gram and toddy.
So why do we need the black Gram or Toddy? Why not use yeast?
Most restaurants and homes today do use yeast and the fermentation when done by yeast results in alcohol as a byproduct (which evaporates when cooking)- These idlis then have a neutral to sweetish taste.
When using Black gram- It's the Lactic acid bacteria that does the trick. So Idli makers who use Black gram use the same principle as bakers who use the sourdough technique for their bread. However in an Idli, one does not need a starter, since the Black gram acts like a magnet for all Lactic acid bacteria that are present in the air. These Lactic acid bacteria then aid the fermentation and their byproduct is- Yup, Lactic acid. Hence they have a sourish flavour. (Acids are sour !)
That is where the Toddy helps- Toddy is formed when the sap of the coconut flower is fermented by wild yeast. So toddy is a good source for yeast in fermentation and like I mentioned earlier, yeast fermentation leads a sweetish taste.
So our idea was to balance the acidic flavour with the sweetish one! Hence we used both Black gram and toddy and they did the tango really well.
The end result: Finger millet and Buckwheat are flavourful grains (unlike rice) add to this the subtle notes of fermentation, we have a lovely breakfast that goes great either with lentils or lightly flavoured chutneys.