Setting Up of a Ghee Refinery

Refinery is the place where refining of ghee is done. Refining as applicable to ghee is to improve its flavour, colour and appearance by adopting physical processes of heating and clarification of raw material and not by any chemical process. Normally raw (Kachcha) ghee or butter or cream collected from small producers is the raw material for refining.

 

i. Refining Facilities and Equipment

Building: Ghee refinery building should be spacious, having proper lighting and ventilation, and facilities for employees comfort and hygiene.Ghee collection vessels: These are normally cylindrical vessels with handles and lids, used exclusively for weighing ghee. The capacity of the vessels is 100 and 200 litres.

Water bath: Water bath is used at several ghee refineries for melting the remnants of ghee adhering to the sides of the tins after emptying the Kachcha ghee in the heating pan. It shall be a shallow vessel with a flat bottom or a tray made up of mild steel.

Heating pans (Karahis/kettles): Karahis are used for heating butter, Kachcha ghee or cream. They shall be constructed with hemi-spherical, dished or conical bottom. The joints in the kettle shall be welded and finished smooth. Double jacketed tie table kettles with provision of heating by steam are preferred over Karahis.Stirrers and scoops: Rods, preferably of stainless steel or aluminum alloy with flattened end on one side and wooden handle on other side shall be used for stirring butter/kachcha ghee/cream to prevent charring of casein and facilitate escape of moisture. For large size heating pans mechanical agitator may be used. The scum that rises on the top may be scooped out with metallic scoops.

Strainer: Before ghee is transferred from the heating pan to the settling tank, it shall be strained through a detachable strainer having an aperture width of not more than 14 mm. The strainer shall preferably be made of stainless steel.Transfer device: Ghee shall preferably be transferred from the heating kettle through a stainless steel pipe and a stainless steel pumping arrangement.

Settling tank: A settling tank should be of the capacity in range of 500 to 6000 litres depending on the requirement. It shall be preferably of the cylindrical type with a conical or dished bottom with suitable arrangement for mounting. The interior corners shall be rounded off facilitating cleaning and complete drainage.The lid shall be in two or more parts and of overlapping type. A central outlet at the bottom of settling tank or a side outlet at a suitable height should be provided for completely draining the tank.A centrifugal clarifier may also be used for clarification of ghee and the clarified ghee may be led to a tank similar to settling tank from where it can be drawn for filling into containers/packaging unit.

Heating source: The method of heating butter or kachcha ghee or cream depends on the scale of refining process. Small to medium sized refineries should built a furnace on which heating pans may be mounted. The furnace may be of the single pan or multiple pan type and made of firebrick and fire clay plaster. The fuel for such furnace may be smoke free wood or charcoal. Modern refineries with large capacity make use of steam heating for which necessary facilities, such as boiler,generator, etc. have to be installed.Filling, sealing and seaming arrangements: Proper arrangement for filling of ghee, depending on the type of packaging system, sealing and seaming of the containers should be made.

Packing room: In the packing room, ghee is filled into tins, cooled for granulation,sealed and labelled. The room should be well ventilated and lighted and shall be insect proof and rodent free. The floor should be maintained dry and clean, and drippings while filling ghee shall not be allowed to spread on the floor.

 

ii. Method of Refining

Refining practices differ in different parts of the country but the basic principle and practices involved are the same. In some parts of the southern states, butter is generally the starting material for processing whereas in the northern and western parts of the country, it is kachcha ghee, which contains considerable amount of buttermilk and suspended solids, such as casein. The heating of butter of kachcha ghee is done in karahis/kettles to a certain temperature depending on the regions.The heating temperature in range of 110-115oC (sometimes even upto 130oC) is maintained for the consumers in the southern states so that mild to strong cooked flavour may be induced in ghee. On the other hand kachcha ghee is heated only to about 70o to 80oC to developed slight acidic to strong curdy flavour for the consumers of northern and western states depending on their preferences. The ghee so produced is transferred to settling tank, where kept undisturbed for 4-12 hours depending on the season. The clarified ghee is fil led into tins adopting asuitable system.

 

iii. Reception of Raw Materials for Refining and Grading

All the butter, kachcha ghee or cream received at the refinery should be subjected to preliminary screening before it is accepted or rejected. Preliminary screening generally consists of only following three tests.

•  Organoleptic examination.
•  Butyro-refrectometer reading at 40oC and
•  Baudouin test.

In doubtful cases, the samples may be subjected to further tests, such as determination of Reichart value and polenske values, and free fatty acid content.