Methods of Manufacture of Ghee

Different methods are used for the preparation of ghee. The adoption of a particular method is mainly dependent on the scale of production. The classification and description of these methods is given as below:

1 Indigenous (Desi) method
2 Direct cream method
3 Creamery butter method
4 Pre-stratification method
5 Continuous method

The flow diagram of the above methods has been schematically shown in Fig.

Flow diagram of manufacturing ghee by different methods

i. Indigenous (Desi) method

It is an age-old process and largely adopted in rural areas/villages and also at urban household levels because of simplicity in equipment and technique. This traditional method of making ghee contributes about 80% of the total ghee produced in the country. This method usually involves two routes, (1) lactic acid fermentation of raw or heated milk is followed by churning of curd into makkhan (butter) and (2) separation of malai (clotted cream) from the boiled milk and its churning into butter.Dahi or buttermilk of previous day is used as starter culture for fermentation of milk. Churning of curd or malai is done with hand wooden churn. Now-a-days electrically operated butter churns are available and used by many housewives or makkhan producers. Makkhan is stored at room temperature for days together and when sufficient quantity accumulated, it is converted into ghee. For this purpose,makkhan is heated in a earthen pot (now-a-days metal, particularly steel or aluminum containers are also used) on slow fire. The scum gathered on the top of melted butter is continuously removed with perforated ladle. The heating is discontinued on complete removal of scum and froth and getting clear fat (ghee). There are several limitations in this process which are mentioned here:

•  The quality of ghee is highly inconsistent in terms of chemical and sensory quality.
•  Method is incompatible to large-scale production.
•  Recovery of fat is low.
•  Acidity is high and hence keeping quality is low.
•  Manufacture and storage of ghee is done in undesirable containers.
•  Ghee residue being acidic in nature cannot be used.

The indigenous method is not adopted by organized dairies. Most of the ghee produced by this method is either consumed for household purpose or serves as a base material for the blending operations at ghee grading and packing centers functioning under Agricultural Marketing and Grading (AGMARK) scheme in India.To overcome the problems associated with desi method an improved indigenous method has been suggested which is as follows:

•  Always pre-filter/strain milk before use.
•  Give suitable heat treatment, preferably boiling the milk before making dahi.
•  Cool milk to room temperature (22-30oC) and then add starter culture for dahi preparation. The setting of dahi should be done under controlled conditions.Incubate milk till dahi is set and desired acidity (0.80 per cent) is developed.It normally requires about 16-18 hrs in winter and 8-10 hrs in summer.
•  Churn dahi by electrically driven beater or butter churn.
•  Use cold water during churning in summer months to minimize the fat losses in buttermilk (lassi), thereby improving the fat recovery in ghee.
•  Make ghee preferably from fresh makkhan or store makkhan in a refrigerator if it is to be converted into ghee after a long period. Don’t store makkhan or ghee in earthenware or copper or iron containers.
•  Heat makkhan (butter) at sufficiently high (more than 100oC) temperature for ghee making.
•  Strain ghee properly so as to make it completely free from residue.

  ii. Direct Cream Method

The small dairies use a technologically improved method for ghee making which involves the separation of cream from milk by centrifugation. This process omits the need for production of butter because cream is directly converted into ghee.The fresh cream or refined cream or even washed cream is heated in a heating kettle to evaporate moisture. The kettle may be an ordinary kettle heated by gas or a steam heated double jacketed kettle made up of stainless steel. The choice of kettle is made on the scale of operation. A steam heated jacketed ghee kettle is fitted with an agitator, steam control valve, pressure and temperature gauges and a movable, hollow, stainless steel tube centrally bored for emptying out the contents.Alternatively provision can be made for a tilting device on the ghee kettle to decant off the product. High fat cream is heated continuously in the kettle with intermittent agitation to avoid burning at initial stage. At last stage temperature should be controlled between 105-110oC. Heating is discontinued as soon as brownish froth appears on the surface and colour of the ghee residue turns to golden yellow or light brown. At this stage ghee is left undisturbed in the kettle so that residue uettles at the bottom. Ghee is allowed to cool to about 60oC and then filtered properly. In case a oil separator is used for removing residue, then ghee is directly passed through the centrifugal separator. The use of plastic cream or washed cream with about 75-80% fat is recommended for minimizing both fat loss and steam consumption. The final product will have a less intense cooked flavour when low SNF (solids not fat) cream is used.

  Advantages

•  Butter churn and butter storage facilities are not required, therefore, less initial costs are needed.
•  No refrigeration facility required for preparation and storage of butter.
•  Recovery of fat on basis of total butterfat is higher than indigenous methods because of elimination of butter making step.
•  The keeping quality of ghee is better.

 Disadvantages

•  Direct cream method requires a long heating time to remove the moisture.
•  A high content of serum solids in the cream may also produce a highly caramelized flavour in the ghee.
•  This method leads to about 4-6% loss of total butterfat in the ghee residue or during handling operations, depending upon the fat percentage in the cream. However, excessive fat from ghee residue may be recovered.
•  Energy consumption in comparison with creamery butter method is higher.