Idli

The Gujarati work Varṇaka Samuccaya (1520 CE) mentions idli as idari, and also mentions its local adaptation, idada (a non-fermented version of dhokla).^[8]

The earliest extant Tamil work to mention idli (as itali) is Maccapuranam, dated to the 17th century.^[9][10] In 2015, Chennai-based Idli caterer Eniyavan started celebrating March 30 as "World Idli Day".^[11]

Preparation

To make Idli, four parts uncooked rice (idli rice or parboiled rice) to one part whole white lentil (black gram, Vigna mungo) are soaked separately for at least four hours to six hours or overnight. Optionally spices such as fenugreek seeds can be added at the time of soaking for additional flavour. Once done soaking, the lentils are ground to a fine paste and the rice is separately coarsely ground, then they are combined. Next, the mixture is left to ferment overnight during which its volume will more than double. After fermentation, some of the batter may be kept as a starter culture for the next batch. The finished idli batter is put into greased moulds of an idli tray or "tree" for steaming. The perforated molds allow the idlis to be cooked evenly. The tree holds the trays above the level of boiling water in a pot, and the pot is covered until the idlis are done (about 10–25 minutes, depending on size). A more traditional method is to use leaves instead of moulds.^[15]

• Making idlis
• 
  Key ingredients used are rice and black gram.
• 
  Idli batter
• 
  Idli mold
• 
  Batter poured into the mold
• 
  Several molds stacked over another
• 
  Idli steaming in cooker
• 
  Cooked idli
• 
  Molds removed from cooker
• 
  Idlis ready to eat

Serving

Since plain idlis are mild in taste, a condiment is considered essential. Idlis are often served with

Variations

There are several regional variations of idlis made in South India and Sri Lanka. With the emigration of south Indians and Sri Lankans throughout the region and world, many variations on idli have been created in addition to the almost countless local variations. Hard-to-get ingredients and differing cooking customs have required changes in both ingredients and methods.

• 
  Idlis cooked traditionally in coconut shells, Karnataka
• 
  Idli served with rasam
• 
  Moode idli steamed in fragrant screwpine leaves, Mangalore, Karnataka.
• 
  Sambar idli as served in Tamil Nadu
• 
  Kotte kadubu idlis steamed in jackfruit leaves, Karnataka
• 
  Rave idli (sooji idli) is a specialty of Karnataka
• 
  Sanna(s), a Goan variant of idli, also known as hittli in Konkani.

Batter fermentation mechanism

Fermentation of idli batter results in both leavening caused by the generation of carbon dioxide as well as an increase in acidity. This fermentation is performed by lactic acid bacteria, especially the heterofermentative strain Leuconostoc mesenteroides and the homofermentative strain Enterococcus faecalis (formerly classified as Streptococcus faecalis). Heterofermentative lactic acid bacteria such as L. mesenteroides generate both lactic acid as well as carbon dioxide whereas homofermentative lactic acid bacteria only generate lactic acid.

Both L. mesenteroides and E. faecalis are predominantly delivered to the batter by the black gram. Both strains start multiplying while the grains are soaking and continue to do so after grinding.

L. mesenteroides tolerates high concentrations of salt unlike most other bacteria. Hence the salt in the batter and the ongoing generation of lactic acid both suppress the growth of other undesirable micro-organisms.^[22][23]

Idli Day

March 30 is celebrated as World Idli Day.^[24] It was first celebrated in 2015 at Chennai.^[25]

See also

References