A Wet grinder is a food preparation appliance used especially in Indian cuisine for grinding food grains to produce a paste or batter. Wet grinding is rare in western cuisine but common in Indian cuisine.^[1][2] Wet grinders are used to make pastes from grains and lentils and is used extensively in South Indian cuisine for preparation of popular dishes such as dosa, idly, vada, appam and paniyaram.^{[3][4][5][6][7]} It consists of a granite stones which rotate inside a metal drum with the help of an electric motor and the food grains get crushed between the stone and drum.^[8]

History

P. Sabapathy developed the wet grinder in Coimbatore in 1955.^[9][1][10] Sabapathy introduced the grinders to other cities such as Chennai and Madurai.^[10] In 1963, P. B. Krishnamurthy started Lakshmi Grinders which led to the commercial popularity of wet grinders.^[11] In 1975, R. Doraiswamy invented the tilting wet grinders.^[12][11] L. G. Varadaraj introduced the table top wet grinders which replaced grinders which had to be placed on the ground.^[13][11]

Manufacturing

Wet grinder consists of granite stones which rotate inside a metal drum with the help of an electric motor and the food grains get crushed between the stone and drum.^[14] Wet grinders have two advantages over electric mixers or blenders. First, the stone grinder generates less heat than a mixer and heat affects the flavor of the food. Second, the stones remain sharp for a greater time than do metal blades.

Industry

As the product was invented in the city, Coimbatore naturally emerged as a center for the manufacture of wet grinders. The availability of raw material in the form of granite stones, electric motor manufacturing units and the necessary heavy equipment such as lathes, drilling and milling machines used in manufacturing aided the development of the industry.^[1] The city contributes to about 75% of the 1 lakh total monthly output of wet grinders in India.^[15] The industry employs 20,000 people directly and provides indirect employment to 50,000.^[1] In 2011, the cluster had a yearly turnover of ₹225 crore (US$31 million) which grew to ₹2,800 crore (US$390 million) in 2015.^[15]

Geographical Indication

In 2005, the Government of Tamil Nadu applied for Geographical Indication for Coimbatore wet grinder.^[16] The Government of India recognized it as a Geographical indication officially since the year 2005-06.^[17]