Help needed, please!

I am at my wits end!

I used to make perfectly good dosas when we were in London. Ever since moving to Leeds, my luck has dried up.

These days, every time I make the batter using rice, urad ratio of 3:1 and using a tsp of fenugreek seeds – it just does not work. Either the batter does not get fermented at all or it rises splendidly, only with a rotten smell! Just does not smell the way fermented batter should smell.

Just to be extra sure, I even tried making a dosa out of this smelly but fermented looking batter – but it tastes un-fermented too! My friends have advised putting the batter in a slightly warm oven, in the boiler room – but nothing works!All this used to work in London, by the way..

Then I thought that maybe my vessels needed sterilizing – tried that – and that failed the test too. Same result.

Then, I found some dosa mix which I had to whizz in the blender and then leave to ferment – exact same result! I have searched high and low on the internet – exhausted my mom’s tips.. And am now hoping that one of you will have some solution!

Any and all suggestions welcome!