2 hours ago, KennethT said:
Oh, you're asking a person who eats this food but never makes it. So I asked an expert, my mother. Bless her, it's my last night in India on this trip, and she offered to make me dosa as I was asking.
We used to grind the grain by hand using an aatukallu.
Thankfully these granite mortar and pestle are mainly ornamental now, as they require a huge amount of manual labour. We have one in the house, but it's no longer used.
In our house in India we soak the urad daal and rice then use a mixi or a grinder like the one you linked. Electromechanical, in any case.
My sisters in the UK use preground flours, readily available in Asian shops in most cities. I'd be lying if I said I could taste the difference.