Equipment for Traditional and Industrial Ghee Production

Ghee – India’s golden clarified butter – has been a kitchen staple for thousands of years. But while the product itself has stayed remarkably consistent, the equipment used to produce it has changed dramatically. From the humble karahi used in village homes to continuous scraped surface heat exchangers running 24/7 in commercial dairies, ghee-making equipment reflects a fascinating journey of scale, efficiency, and engineering. Whether you’re studying dairy technology or planning a ghee production unit, understanding this equipment is essential.

Traditional ghee making equipment 🔗

The traditional or desi method of ghee making is an age-old process still widely practised across rural India. According to the INFLIBNET e-PG Pathshala course on dairy technology, the indigenous method involves placing makkhan (traditional unsalted butter obtained by hand-churning whole milk dahi) in a vessel and heating it to about 110-120°C with constant stirring until virtually all the moisture evaporates. The ghee residue is then separated by filtration.

This traditional approach accounts for a significant share of total ghee production in the country, estimated at roughly 80%, owing to the simplicity of equipment and technique involved.

The karahi (kadhai) 🔗

The karahi is the centrepiece of traditional ghee production. It is a heavy-bottomed, wide, shallow pan – typically made from copper, brass, or stainless steel. Its design is deceptively simple yet well-suited for the job. The wide surface area maximises contact between the butter and heat, promoting faster moisture evaporation. The curved sides make continuous stirring and scraping easier.

Copper karahis are particularly valued because copper is an excellent heat conductor, providing even heating that reduces the risk of burning milk solids at the bottom. In many rural households and small-scale operations, the karahi is placed over a wood fire or an LPG stove, and heat intensity is adjusted manually.

Wooden ladles and scrapers (khunti) 🔗

Alongside the karahi, traditional ghee makers use wooden ladles and scrapers, locally called khunti. Wood is preferred because it does not conduct heat – protecting the maker’s hands during long stirring sessions – and it does not scratch the pan surface. The constant scraping with the khunti ensures better heat transfer and prevents milk solids from sticking to the pan and burning, which would give the ghee a bitter, off-flavour.

Skill-based heat control 🔗

In traditional methods, temperature control is entirely manual and experience-based. A skilled ghee maker judges the right temperature by watching the butter’s behaviour – the pattern of bubbling, colour changes in the milk solids, and the characteristic nutty aroma that develops as water evaporates. When the effervescence subsides, fine air bubbles appear on the surface, and the curd particles turn golden-brown, the ghee is ready.

While this method produces ghee with rich, complex flavours, it has clear limitations: it is labour-intensive, time-consuming, difficult to scale, and harder to maintain hygienically. For these reasons, the dairy industry moved toward mechanised alternatives.

Modern ghee kettles (ghee boilers) 🔗

As demand for ghee grew and commercial dairies needed consistent quality at higher volumes, modern ghee kettles (also called ghee boilers) emerged as the standard equipment for batch-based industrial ghee production. These kettles bridge the gap between traditional craftsmanship and industrial efficiency.

Construction and design 🔗

A modern ghee kettle is a double-walled, jacketed vessel – either hemispherical or cylindrical in shape. The inner shell is typically made of SS 316 grade stainless steel (around 6 mm thick), the intermediate shell of mild steel, and the outer shell of SS 304 grade steel. The vessel is insulated to prevent heat dissipation. The hemispherical bottom design is especially common because it facilitates uniform heating and easier scraping of residue.

Steam heating: the key advantage 🔗

Unlike traditional karahis that use direct flame, modern ghee kettles use steam as the heating medium. Live steam – typically at a pressure of about 3.0 kg/sq.cm – circulates through the jacket surrounding the inner vessel. This indirect heating method offers several critical advantages:

Precise temperature control – Steam pressure can be gradually increased or decreased, giving operators fine control over temperature. This is essential because the final stage of ghee production (when milk solids brown and flavour develops) requires careful heat management to prevent burning.

Elimination of hot spots – Direct flame heating often creates localised hot spots that scorch milk solids. Steam provides even heat distribution across the entire vessel surface.

Better hygiene – Enclosed jacketed vessels are far more hygienic than open karahis. Many modern kettles are compatible with CIP (Clean-in-Place) systems, allowing thorough cleaning without disassembly.

Motorised scrapers and stirrers 🔗

Modern ghee kettles are fitted with motorised scraper-stirrer assemblies that rotate continuously inside the vessel. These scrapers serve the same purpose as the traditional khunti – they prevent milk solids from adhering to the heated wall and burning. However, motorised scrapers do this far more consistently and without manual labour. The scraper blades are designed to maintain close contact with the vessel wall, ensuring efficient heat transfer throughout the process.

Capacity and suitability 🔗

Ghee kettles are available in a range of capacities – commonly from 100 litres to 2,000 litres per batch, and some large operations use kettles that handle even more. This makes them suitable for small to medium-scale dairy plants. Typical batch sizes range from 50 to 500 kilograms of ghee output. The creamery butter method – where unsalted butter is melted at 60°C, loaded into the ghee boiler, and gradually heated to 90°C until moisture is removed – is one of the most commonly employed processes in these kettles.

Process in a modern ghee kettle 🔗

The general process in a ghee kettle follows these steps:

Loading – Butter or cream is loaded into the kettle. If butter is used, it is first melted at around 60°C before being transferred to the boiler.

Heating – Steam pressure is gradually increased to raise the temperature to about 90°C. At this stage, moisture begins to evaporate vigorously. The temperature remains relatively constant as long as water is still present.

Final clarification – Once most moisture is removed, the temperature rises further towards 110-120°C. Scum that collects on the surface is regularly removed. The endpoint is indicated by the disappearance of effervescence, the appearance of fine air bubbles, and the browning of curd particles.

Filtration and cooling – The ghee is separated from the residue using stack filters, pressure filters, or centrifugal clarifiers. The clarified ghee is then cooled to about 40-42°C before packaging.

Continuous ghee-making machines 🔗

For very large-scale production – where dairies need to produce several tonnes of ghee per day – batch kettles become a bottleneck. This is where continuous ghee-making systems come in. These sophisticated systems can operate around the clock with minimal manual intervention, delivering consistent product quality at high throughput.

The scraped surface heat exchanger (SSHE) 🔗

The core component of a continuous ghee-making system is the scraped surface heat exchanger (SSHE). This is a cylindrical chamber with a rotating shaft fitted with scraper blades. As butter or cream flows through the chamber, the scrapers continuously remove any material that adheres to the heated inner wall.

SSHEs prevent fouling on the heat transfer surface by constantly scraping off accumulated deposits, which maintains a clean surface and results in higher overall heat transfer efficiency. This is especially important for ghee production because, as water evaporates and milk solids separate, the mixture becomes thicker and stickier – exactly the kind of product that would foul a conventional heat exchanger.

The NDRI continuous ghee system 🔗

A well-known continuous ghee production system was developed by the National Dairy Research Institute (NDRI), Karnal. According to the INFLIBNET technical resource, this system consists of a receiving-cum-heating vat for cream or white butter, a gravity separator, a scraped surface heat exchanger coupled with vapour separators, and positive displacement pumps to move the raw material through the system. Final heating takes place at about 110-115°C in the SSHE, just as in the batch method.

The NDRI equipment is described as a three-stage pressurised, swept-surface separator with a sanitary design. Several major dairy plants in India – including Mother Dairy (Gandhinagar, Gujarat), Panchamrut Dairy (Godhra, Gujarat), and Nestle (Moga, Punjab) – have adopted this continuous principle for ghee production.

How a continuous system works 🔗

In a continuous ghee-making line, the process flow typically looks like this:

Feed preparation – Cream or melted butter is fed into a balance tank and pumped at a controlled flow rate into the system.

Heating via SSHE – The feed passes through the scraped surface heat exchanger, where it is heated rapidly. The rotating scraper blades ensure that the product film on the heat transfer wall is continuously renewed, preventing burn-on and ensuring uniform heating.

Vapour separation – As moisture evaporates under the high temperature, the resulting vapour is continuously removed by vapour separators integrated into the system. This eliminates the need to wait for moisture to boil off, as in batch processing.

Clarification and filtration – The crude ghee passes through centrifugal separators or filter systems that remove milk solids and any remaining impurities. Modern systems can automatically adjust separation intensity based on the level of impurities detected.

Cooling and packaging – The clarified ghee flows to a ghee cooler, is brought down to the appropriate temperature, and then moved to filling and packaging lines.

Advantages of continuous systems 🔗

Continuous ghee-making machines offer several significant benefits over batch kettles:

High throughput – These systems can handle capacities of several thousand litres per hour, making them essential for large commercial dairies.

Consistent quality – Automated control of temperature, flow rate, and separation parameters ensures that every batch meets the same standards. Some advanced systems incorporate sensor-based monitoring that can make real-time adjustments.

Reduced labour – Unlike traditional or even semi-automated kettle operations, continuous systems require minimal manual intervention once set up and calibrated.

Better hygiene – Enclosed processing with CIP-compatible design minimises the risk of contamination.

Energy efficiency – Continuous operation with optimised heat exchange generally uses less energy per kilogram of ghee produced compared to batch methods.

Equipment maintenance across methods 🔗

No matter which type of ghee-making equipment is used, proper maintenance is non-negotiable for producing quality ghee. Traditional karahis require regular seasoning and careful cleaning to prevent off-flavours from developing over time. Modern ghee kettles need periodic inspection of their heating jackets, scraper blades, sealing systems, and steam connections.

Continuous systems demand the most rigorous maintenance protocols – regular calibration of sensors, cleaning of heat exchange surfaces, and timely replacement of scraper blades. However, this investment in maintenance pays off through consistent output and reduced downtime.

Quality standards for ghee in India 🔗

Regardless of the equipment used, the final product must meet established quality parameters. In India, ghee marketed through organised dairies carries Agmark certification, which classifies ghee into three grades based on free fatty acid (FFA) content: Special grade (max 1.4% FFA), General grade (max 2.5% FFA), and Standard grade (max 3.0% FFA). Additionally, the moisture content must not exceed 0.3%, and the Baudouin test (which detects adulteration with hydrogenated vegetable fat) must be negative.

The FSSAI (Food Safety and Standards Authority of India) defines ghee as pure clarified milk fat derived solely from milk, curd, desi butter, or cream, with no colouring matter or preservatives added. Meeting these standards requires not just good raw materials but also well-maintained, properly operated equipment at every stage of production.

Choosing the right equipment 🔗

The choice of ghee-making equipment depends primarily on production scale, budget, and the desired product characteristics. A small dairy or household producer may find a traditional karahi or a small ghee kettle perfectly adequate. Mid-sized dairy plants typically invest in steam-jacketed ghee kettles with motorised scrapers, which offer a good balance of quality, efficiency, and affordability. Large-scale commercial operations – those producing tonnes of ghee daily – need continuous systems built around SSHEs to remain competitive.

It’s also worth noting that the production method influences flavour. Traditional slow-cooked ghee often has a deeper, more complex flavour profile due to the gradual browning of milk solids. Industrial methods, while producing cleaner and more consistent ghee, may not fully replicate those nuanced flavours – which is why traditionally made ghee (especially using the Bilona method) often commands a premium in the market.

What do you think? As dairy technology continues to advance, can industrial equipment ever fully replicate the flavour and aroma of traditionally made ghee? And for small-scale producers looking to grow, at what point does upgrading from a karahi to a ghee kettle become essential?

References

1. https://ebooks.inflibnet.ac.in/ftp04/chapter/technology-of-ghee-making-direct-cream-creamery-butter-continuous-method/
2. https://shahjighee.com/5-ghee-making-process-which-process-is-best-shahijghee/
3. https://www.abfindia.co.in/ghee-making-equipment.html
4. https://www.skylarkpune.com/ghee-making-equipments.html
5. https://varadrajindustries.com/ghee-plant-equipments.html
6. https://khatabook.com/blog/ghee-manufacturing-methods/
7. https://www.spxflow.com/scraped-surface-heat-exchangers/