Skip to content
FriendsPantry

Indian techniques · intermediate

Wet grinding

Also: pisai, araippu (Tamil), sil-batta grinding

Grinding soaked grains, pulses, coconut or spices with water into a smooth paste or batter.

224 recipes use it

What it is

Wet grinding turns soaked rice and urad dal into idli and dosa batter, fresh coconut and spices into the masala pastes of south Indian, Goan and coastal cooking, and onions, ginger, garlic, chillies or cashews into curry pastes. It was traditionally done on a grinding stone (sil-batta, ammikal, attukal) and today in stone wet grinders or blenders.

Why cooks use it: Water lets solids break down into fine, smooth pastes and aerated batters. For idli and dosa batter, properly ground and aerated urad dal gives soft, spongy idlis and crisp dosas.

The science

Soaking hydrates starches and proteins so they shear easily. Urad dal contains mucilage-like substances and proteins that trap air when ground well, which supports the rise during fermentation. Grinding generates heat, which can dull flavours and in batters can encourage early, unwanted fermentation or spoilage, so keeping it cool matters.

Starch gelatinisationEmulsionsMoisture and textureAroma compounds and flavourYeast fermentationLactic acid fermentationChanging texture: tenderising and crisping

Step by step

  1. Soak grains or pulses as required (urad dal and rice about 4–6 hours, separately).

  2. Drain and grind in batches, adding cold water a little at a time.

  3. Grind urad dal until light, fluffy and smooth (it should increase in volume); grind rice slightly coarse, like fine semolina, for idli.

  4. For masala pastes, add the hardest spices first, then coconut, then soft aromatics.

  5. Stop the machine to scrape down and check temperature; let it rest if it gets warm.

  6. Combine batters and mix with clean hands, then proceed to fermentation or cooking.

Heat and timing

Time: Urad dal 15–30 minutes in a stone grinder, a few minutes in a blender; masala pastes 1–3 minutes.

How you know it’s right

  • Urad batter fluffy, glossy, and a drop floats in water
  • Coconut paste smooth with no visible shreds (or coarse if the recipe asks)
  • Batter thick enough to coat the hand

Common mistakes

  • Adding too much water at once, making a thin batter
  • Overheating the blender
  • Grinding urad and rice together in a small blender (texture suffers)

Troubleshooting

Batter too thin
Add a little rice flour or semolina; next time add water gradually.
Blender overheating
Grind in smaller batches, use ice-cold water, and pause between runs.
Gritty paste
Grind longer, soak longer, or use a smaller jar so the blades catch the food.

Restaurant DNA

How professionals do it

South Indian restaurants grind batter daily in large stone wet grinders, which grind slowly with less heat and give a fluffier urad batter than high-speed blenders.

At home

A tabletop stone wet grinder is worth it if you make idli and dosa often; otherwise a powerful blender with ice-cold water, in batches, works.

General professional practice — not any particular restaurant’s recipe.

Food safety

  • Unplug grinders before scraping down.
  • Use clean equipment for batters that will ferment.

Practise it

215 more