What You Need to Know
Utilizes a cylindrical grinding stone (kallu) on a flat granite slab to shear cell walls without pulverizing. Unlike metal blades, stone microporosity retains essential oils. The technique specifically avoids temperatures exceeding 40°C to prevent terpene degradation.
Critical for authentic podi (spice powders) and wet chutneys where emulsion stability matters. The slow grinding allows gradual oil release from mustard, cumin, and urad dal without generating bitter oxidized compounds seen in blender preparations.
Key Parameters
Temperature
°C - °C
Time
12-18 min
3 min (simple powders) - 45 min (complex wet-dry mixes)
Equipment
Black granite slab (≥5cm thick)Cylindrical roller stone (≈15cm diameter)Brass scraper (for collection)
Steps
- 1.
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The Science
Primary Reaction
Mechanical cell rupture (not thermal or chemical)