In Jainism, especially during Parshushan (Paryushan) Parva, there are specific dietary restrictions observed by devotees to practice self-restraint and purity. The consumption of idli during Parshushan depends on how it is prepared:

1. Fermentation: Traditional idli batter is fermented overnight. During Parshushan, many Jains avoid consuming any food that is fermented or kept overnight, as it is believed to increase the presence of microorganisms, which goes against the principle of ahimsa (non-violence).

1. Fresh Preparation: If the idli is made from freshly ground batter and cooked immediately without fermentation or keeping the batter overnight, some Jain families might consider it acceptable. However, this practice can vary depending on sect and family traditions.

Summary: Idli made from fermented or overnight batter is generally not consumed during Parshushan by Jains. If the idli is made fresh without fermentation, it may be allowed in some traditions, but it is best to consult your family or community elders for guidance.

Always remember, the core principle is to avoid harm to even the smallest living beings, and foods that promote microbial growth (like fermented items) are typically restricted.