Batter was made from "double horse" idli mix (which by label only contains rice and urad dal), plus a few fenugreek seeds, ground in a blender as the package recommends, fermented 24h, in european summer climate, then stored in fridge for a day, looks fine though a bit lumpy raw. No strong off smells as far as I can judge.
When steamed (~20 min) in an idly steamer (which I am not yet very familiar with), the cooked result seems fine but has brown streaks throghout - as if someone swirled caramel or chocolate into the batter. Texture, taste, smell seem fine.
Pot with a whistle, but non-pressurizable. Did not run dry. Batter in raw form has no dark streaks. Equipment clean. Blender might have had traces(!) of cashews, limoncello, sugar, soymilk in it.
Is this a fermentation fault, or can using too much heat to drive the steamer cause some kind of burn/caramelization? Is this anything potentially unsafe happening?
Outside does look caramelized where there are streaks indeed, can the inside swirl be due to steam jets through the steamer holes?
Same mix (not sure if I added the fenugreek), same steamer, same time (not sure about same heat) worked before.