Is Ghee your favorite dairy product? If yes, then this article is a must-read for you as you can learn how advanced dairy processing plants manufacture your favorite dairy product. Let us delve deep into the process of the Ghee Manufacturing Plant that transforms milk into ghee to add flavor to your favorite dishes as well.
Origin & History of Ghee Production
Ghee is one of India’s oldest and most important traditional milk products. It was produced in ancient India as far back as 1500 BC. In ancient India, ghee was the most popular cooking medium with great use in the Ayurvedic system of medicine. Ayurveda, a holistic system of medicine, believes that ghee promotes longevity and protects the body from various diseases.
Ghee is similar to products found in other parts of the world since ancient times. In Egypt, its name is Samna; in Sudan, Samin; in the Middle East, Maslee; in Iran, Rogan; and in Uganda, Samuli.
Additionally, ghee is gaining popularity in Australia, Arabian countries, the United States, the United Kingdom (UK), Belgium, New Zealand, the Netherlands, and many other African and Asian countries. Note that, although the names are different, the process of manufacturing is similar in all cases across the world.
Composition of Ghee
According to the Food Safety and Standard Regulations issued by FSSAI, the ghee that you consume holds the following composition:
- Ghee holds a combination of saturated fat (around 65%), unsaturated fat (around 5%), and monounsaturated fat (around 25%).
- Its saturated fat primarily consists of easy-to-digest short-chain fatty acids (89%).
- Both saturated and unsaturated fats play an important role in a healthy diet.
- Ghee also contains fat-soluble vitamins A, D, E, and K, small amounts of essential fatty acids (arachidonic acid and linoleic acid), charred casein, and traces of calcium, phosphorus, iron, and zinc.
- The free fatty acid content is 3.0% (as a percentage of oleic acid).
Cow ghee has nearly 5% less saturated fat than buffalo ghee. It also contains carotenoids, which give it a yellow hue. Buffalo ghee, on the other hand, lacks carotenoids but contains biliverdin and bilirubin, which give it a greenish tint.
Methods of Ghee Manufacturing in Advanced Dairy Plants
The principles of ghee manufacturing in dairy plants are as follows:
- Concentration of milk fat. This can be done by separating the cream from the milk, or by churning the milk to produce butter.
- Heat clarification of the fat-rich milk portion. This involves heating the milk fat to a high temperature, which causes the water to evaporate and the milk solids to coagulate. The resulting liquid is “ghee”.
- Removal of the curd content. This can be done by straining the ghee through a fine mesh, or by centrifuging it.
There are five methods of ghee making which are as follows:
- Desi or Indigenous Method
- Direct Cream Method
- Creamery Butter Method
- Prestratification Method
- Continuous Method
Desi or Indigenous Method for Ghee Preparation (Homes & Small Scale Ghee Manufacturers)
In rural areas, this age-old practice involves culturing excessive milk and keeping it overnight for fermentation. The resulting curd is then churned using hand-driven wooden beaters to separate the milk fat in the form of desi butter.
Another slightly different method involves heating milk continuously to about 80 degrees Celsius. The malai (creamy layer) that forms over the surface is then collected manually and churned to produce desi butter.
After collecting desi butter over a period of time, the butter is melted in a metal pan or earthenware vessel on an open fire. The extent of frothing indicates when to stop heating. Heating should be stopped when sudden foaming appears, and the contents should be left undisturbed after heating. Curd particles will settle down over time after which the clear fat is carefully decanted.
This method only recovers up to 85% fat.
Direct Cream Method of Ghee Manufacturing Plant
This process begins by separating cream from milk using a centrifuge. The cream is then heated to 114±2°C in a stainless steel, jacketed ghee kettle. The kettle is equipped with an agitator, steam control valve, pressure, and temperature gauges. A movable hollow stainless tube with a central bore is also included for emptying the contents. Alternatively, a tilting device can be used to decant the product from the ghee kettle.
The heating process is stopped as soon as the color of the ghee residue changes to golden yellow or light brown. Initially, there is a great deal of effervescence and crackling sounds during the early stages of boiling. However, these gradually subside as the moisture content decreases. When almost all of the moisture has evaporated, the temperature of the liquid medium will suddenly increase. At this point, it is important to carefully control the heating process.
The appearance of a second, more subtle effervescence indicates the endpoint of the process. This is accompanied by the browning of curd particles. The typical ghee flavor will also be present at this stage, indicating that the preparation of ghee is complete.
One advantage of this method is that it does not require the production of butter prior to ghee manufacturing.
Creamery Butter Method of Ghee Manufacturing Plant
The standard method used in most organized dairies is as follows:
White butter (unsalted) is the raw material in this process. Butter mass or butter blocks are subject to 60°C to 80°C heat in a butter melter. The molten butter then goes into the ghee boiler for further heating using steam as a heating medium.
The steam pressure is increased to raise the temperature. Scum that forms on the surface of the product is removed from time to time with a perforated ladle. The heating is stopped when the effervescence disappears, finer air bubbles appear on the surface of the fat, and the curd particles brown. This is when the ghee develops its characteristic aroma.
The final heating temperature is adjusted to about 114±2°C. Heating beyond this temperature is also sometimes done to achieve a cooked flavor. The ghee is then filtered through an oil filter into a settling tank.
Pre-stratification Method of Ghee Manufacturing Plant
Butter, in this stage, comes from aged cream that has a fat content of 38 to 40%. A continuous butter-making machine or a batch churn processes the cream. The resulting butter is then melted at 80°C and transferred to a ghee kettle or boiler. The molten butter is kept undisturbed in the ghee kettle at a temperature of 80-85°C for 30 minutes.
During this time, the mass of the butter stratifies into three distinct layers. The top layer consists of denatured protein particles (curd particles) and impurities that float to the surface of the butter. The middle layer consists of clear fat. The bottom layer consists of buttermilk serum, which contains 80% of the moisture and 70% of the solids-not-fat in the butter.
After 30 minutes, the butter is skimmable. The top layer of curd particles and impurities is skimmed off. The middle layer of clear fat is then skimmed off. The bottom layer of buttermilk serum is discarded. The remaining two layers are combined to produce finished butter.
The bottom layer is carefully removed without disturbing the top and middle layers. The middle layer, which is mostly fat, is heated to 114±2°C along with the top layer of floating curd particles and denatured protein. This step is necessary to develop the characteristic ghee aroma. Milder flavored ghee can be produced because most of the curd content is removed before the final clarification temperature of the ghee.
This method, although it seems to be complex, holds various advantages which are as follows:
- Removal of buttermilk (bottom layer) eliminates prolonged heating for evaporation of the moisture
- Formation of a significantly low quantity of ghee residue
- A low quantity of ghee absorbed into ghee residue so less fat loss along the ghee residue
- Production of ghee with lower FFA and acidity
Continuous method of Ghee Production for high volumes
This method helps in meeting the need for high-volume production and overcomes the limitations of the batch method. However, although this process facilitates high volume generation of ghee, it comes with various limitations like the following:
- High energy consumption due to low heat transfer coefficient.
- Unsatisfactory cleaning and sanitation of equipment.
- Equipment and processes are not suitable for large-scale production.
- Slippery floor due to ghee spillage.
- Higher handling losses.
Owing to the above reasons, many advanced dairy processing plants like Dollon’s avoid this process, however, for a small ghee manufacturing plant, it comes with the the following advantages:
- Improved product quality control.
- Only a small amount of raw material is held in the plant at any given time, reducing the risk of a whole batch being spoiled.
- Foreign object contamination can be minimized.
- No foaming of the product during production.
The different process of ghee preparation holds different significance for manufacturers to meet the market demand. However, whenever your favorite ghee gets packed, the process is strictly in adherence to food safety regulations and hygiene control protocols. Therefore, never worry about the quality until the product is within the date range of use. There are various benefits of ghee consumption that are seldom known to all of us. Read our article on the benefits of ghee consumption to know whether you are doing it right or not!
