When we make dosa batter, we use the Instant Pot’s yogurt mode to make life easier. Using this setting takes the guesswork out of keeping it warm enough to ferment.  When you use the Instant Pot, it will take about 10 to 12 hours for the dough to rise. You’ll know it is ready once the dough has doubled in size. But, keep in mind, the time will vary some based on where you live. If you live in a cooler environment, you might have to wait a longer time than if you live in a warmer climate.