The cooking of oil seeds is generally done in heating kettles or tempering trough. The heating kettles are normally round shaped cylindrical vessels, stream jacketed both at its base and sides or at its base only. Various types of kettles are available in the market. These kettles are equipped with agitators and open steam admission arran-gements. The kettles may be from one high to five high depending on the seed and design. Another device employed for cooking the meal is called “Tempering Through” and consists of a steam jacketed conveyor may be either single staged or double staged, in the latter case two conveyors are placed one above the other, with suitable discharges ends, and driving arrangements. In this the meal takes longer time to travel and is thus cooked better than in a single staged kettle.

Open steam is supplied to the meal at the entrance by means of a stream nozzle. Thus automised steam gets well mixed up with meal to be heated for giving the requisite moisture content. The slow forward movement of the meal effect a thorough cooking.

If the seed is cooked carefully at critical temperature and critical moisture required for the seed, the efficiency of the expeller can increase by 50% or so.