How Besan is Manufactured from Chana Dal

Besan – the golden, earthy flour found in kitchens across the Indian subcontinent – has a surprisingly structured manufacturing process behind it. Gram flour, as it is known in English, is produced by grinding chana dal (split Bengal gram) into a fine powder. Whether it is going into crispy pakoras, soft dhokla, or melt-in-the-mouth ladoos, the quality of besan depends directly on how it was milled, sieved, and packaged. Understanding this process helps explain why commercially produced besan looks, feels, and performs so consistently – and why the choice of milling technology matters so much.

What is besan and where does it come from? 🔗

Besan is a pulse flour made from chana dal – the hulled and split form of desi chickpeas (Cicer arietinum), also known as Bengal gram. Desi chickpeas are small, angular, and brownish in color – quite different from the larger Kabuli variety used in hummus and Mediterranean cooking. Around 80 percent of desi chickpeas are processed into chana dal, and about 80 percent of that chana dal is further ground into besan. This makes besan one of the most important value-added products in pulse processing.

Besan is naturally gluten-free and rich in protein, fiber, and B vitamins. It also has a low glycemic index, which makes it a good dietary choice for people managing blood sugar levels. These nutritional qualities make it essential that the milling process does not compromise the dal’s inherent properties through excessive heat or contamination.

Raw material preparation: the foundation of good besan 🔗

Before any grinding takes place, the chana dal must be properly cleaned and conditioned. The first stage involves eliminating pebbles, broken grains, and other impurities from the gram. This is not a minor step – leftover stones or grit can damage milling equipment and contaminate the final product.

After cleaning, the dal is conditioned. Conditioning refers to adjusting the moisture content of the dal before grinding. Any excess water must be removed, typically by sun-drying, to keep the moisture level between 12 and 14 percent. Getting moisture right is critical: too much moisture causes the flour to clump during milling, while too little can affect grinding efficiency and flour texture.

In mill units that start from whole chickpeas rather than pre-processed dal, de-husking is performed first – separating the outer skin from the cotyledons (the inner seed halves) – which improves color, digestibility, and texture of the final product. The cotyledons are then split to yield chana dal, which becomes the input for besan milling.

Size reduction: the core step in besan manufacture 🔗

Size reduction – the mechanical breaking down of chana dal into fine flour – is the heart of the entire besan manufacturing process. The equipment used at this stage largely determines the fineness, texture, and recovery rate of the final product. Two broad approaches exist: small-scale milling using traditional equipment, and large-scale industrial milling using high-capacity machinery.

Small-scale method: burr mills and disc shellers 🔗

Small and cottage-scale besan production typically relies on burr mills. These machines use two revolving abrasive surfaces – the burrs – to crush and grind chana dal progressively. The gap between the burrs can be adjusted to control the coarseness or fineness of the flour. The cleaned dal is fed into the hopper, passes through the gap between the rotating surfaces, and is gradually reduced to powder. The ground material may pass through the gap more than once until it reaches the desired consistency.

Disc shellers are another option at this scale. These use rotating discs with abrasive surfaces to break down the dal through friction and impact. They handle varying moisture content reasonably well and require relatively simple maintenance. However, operators must monitor grinding carefully – overheating during milling can affect the flour’s colour and reduce its nutritional value.

After grinding, the flour is passed through a hand-operated or mechanical sieve to separate fine besan from coarser particles. Any oversized material is re-ground until it passes through the sieve mesh.

Large-scale method: hammer mills and reel sieves 🔗

Industrial besan production is dominated by the hammer mill method. Size reduction in a hammer mill occurs through repeated hammer impacts, along with particles accelerating into each other, interrupter plates, and screen surfaces. The dal is fed into the grinding chamber where rapidly rotating hammers pulverise it against fixed screens. The ground material is forced through the screen openings, and only particles fine enough to pass through exit the chamber. Oversized particles remain inside and are ground further.

After grinding, the material is carried towards a classifier for size separation, with oversized particles returned to the crushing chamber for further grinding. A dust collector is fitted in the system to prevent loss of fine powder during operation. This closed-loop design is important: it reduces waste and maximises yield.

The fineness of besan produced by hammer mills depends on the mesh size of the screens used. Coarser flours are produced at around 35 mesh, medium flours at about 70 mesh, and very fine besan grades at 200 mesh or finer. Industrial producers select screen specifications based on end-use requirements – bakery-grade besan, for example, demands a finer grind than household-grade flour.

Sieving: achieving consistent texture 🔗

Whether at a small or large scale, sieving after grinding is non-negotiable. It separates flour that meets the desired particle size from material that needs further milling, and it removes any remaining impurities.

At the industrial scale, reel sieves are the equipment of choice. These are cylindrical, rotating sieves that run continuously during production. Ground material enters the reel, and properly sized particles pass through the mesh while oversized material is retained and routed back to the mill for reprocessing. The gradual milling system adopted in quality besan production involves a sequence of breaking, scalping, purification, reduction, and dressing stages – meaning the sieving operation is not a single pass but a structured multi-step process.

For very fine-grade besan destined for commercial food manufacturing, rotary sifters (also called rotary sieves) are used alongside or after reel sieves. Rotary sifters work to remove insects, stones, and other contaminants during chana dal manufacturing, and a specially fitted auger moves product into a screening chamber where paddles apply centrifugal force to push fluidized particles across the screen surface. Finer particles discharge into the collection hopper while coarser material exits through a separate outlet for re-milling.

Recovery rate and losses during milling 🔗

The recovery rate – the percentage of input dal that becomes usable besan – is a key efficiency metric for any milling operation. The most important factor identified across several industry surveys is the recovery rate, and flour millers select raw material primarily on this basis.

Losses during besan milling occur mainly due to two factors: dust generated during hammer milling, and minor burning of flour particles that come into sustained contact with high-speed rotating parts. Modern industrial systems minimise dust loss through integrated dust collectors and bag filters. Advanced besan milling systems with air classifiers and jet product collectors are designed to ensure 99 percent material passing, keeping losses to a minimum. In well-run operations using updated equipment, the overall recovery rate of besan from chana dal is typically high, with losses limited to a small percentage from dust and heat.

Outdated or poorly maintained equipment tells a different story. Many smaller milling units across India use outdated pulverisers that lead to lower recovery rates, and the milling and sieving process may need to be repeated several times to achieve the required fineness, increasing processing time, energy costs, and risk of product loss.

Finishing and packaging 🔗

Once the besan has passed through milling and sieving and meets quality specifications, it moves to the finishing stage. In some operations, batches of finished besan are blended together to achieve uniform properties, colour, and characteristics across the final product. This is especially common in large commercial mills that serve retail and institutional buyers who expect consistency across every batch.

Moisture control remains important right through to packaging. Besan with excess moisture clumps during storage and has a shorter shelf life. Milled flour is allowed to cool and stabilise before it is packed.

Packaging formats depend on the target market. Bulk supply to sweetmakers, hotels, and caterers typically uses gunny bags or poly-lined gunny bags. Consumer retail packs use laminated pouches that offer better moisture and aroma protection. The market demand for besan largely depends on freshness, quality, and fineness of grinding – so packaging that preserves these qualities is a direct commercial priority for millers. In India, compliance with FSSAI hygiene standards is mandatory for commercial besan production.

Small-scale vs. large-scale: choosing the right approach 🔗

The choice between small-scale burr milling and large-scale hammer milling is not simply about production volume. It comes down to the target market, investment capacity, and required flour quality. Small-scale units using burr mills or disc shellers can serve local markets with moderate output and relatively low capital investment. However, the fineness and consistency achievable is limited compared to industrial operations.

Large-scale hammer mill setups – with integrated reel sieves, rotary sifters, dust collectors, and automated classifiers – produce besan with uniform particle size and significantly lower manual intervention. Industrial besan milling systems are designed to handle capacities ranging from 100 kg/hr up to 3,000 kg/hr, covering everything from small processing units to large commercial mills. The trade-off is higher capital expenditure and the need for technical expertise to operate and maintain the equipment.

For farmers, cooperatives, and rural entrepreneurs, government schemes such as the PM Formalisation of Micro Food Processing Enterprises (PM FME) Scheme, run by the Ministry of Food Processing Industries, provide financial and technical support for upgrading existing micro food processing units – including besan mills – to meet quality and hygiene standards.

What do you think? Given that the recovery rate is the single most important efficiency metric in besan milling, how significant do you think the gap in profitability is between a traditional small-scale burr mill and a modern hammer mill setup with dust recovery systems? And with India producing over 10 million tonnes of desi chickpeas annually – more than half of which goes into besan – what role should small-scale rural processors play in capturing more of that value?

References

1. https://en.wikipedia.org/wiki/Gram_flour
2. https://blog.praterindustries.com/mills-for-chana-dal-processing
3. https://pipingpotcurry.com/making-chickpea-flour-besan/
4. https://www.jasenterprise.com/besan-plant.html
5. https://www.tourism.rajasthan.gov.in/content/dam/agriculture/Rajasthan%20Agricultural%20Competitiveness%20Project/ABPFTechDPR/RACP_ABPF_Tech%20DPR_Besan%20Mill.pdf
6. https://www.rieco.com/solutions/grinding-solutions/besan-grinding-plant