Cashew Processing Setup: Shelling, Peeling, and Grading Business

Cashew processing is a highly lucrative agribusiness in India, which is one of the largest consumers and exporters of cashew kernels globally. Raw cashew nuts harvested from the field cannot be consumed directly because their outer shell contains a corrosive oil called cashew nut shell liquid (CNSL), which can cause skin irritation. Processing is required to safely crack the hard shell, peel off the inner seed coat, and extract the delicious edible kernel. Establishing a commercial cashew processing facility requires careful planning, starting from sourcing raw cashew nuts (RCN) to selecting processing machinery and implementing strict quality standards. This guide covers the operational steps, machinery specifications, licensing, and financial aspects of starting a cashew processing unit.

Raw Cashew Nut Sourcing

Sourcing high-quality raw cashew nuts consistently is the most important factor in determining the profitability of a processing plant. Processors source RCN from domestic growing states such as Maharashtra, Goa, Karnataka, Kerala, Tamil Nadu, Andhra Pradesh, Odisha, and West Bengal. Domestic harvesting occurs between March and June. To run the processing unit year-round, processors also import RCN from West African and East African nations, including Ivory Coast, Guinea-Bissau, Tanzania, Benin, and Ghana. Key quality parameters for RCN include the outturn (measured as the weight of kernels in pounds obtained from an eighty-kilogram bag of RCN), nut count (number of nuts per kilogram), and moisture content. Moisture must be below eight percent for safe storage in ventilated warehouses. Raw crop quality, moisture content, and final recovery rates vary depending on variety, regional weather, and storage efficiency. Sourcing planning must also consider shipping delays, import duty structures, and regional trade policy shifts. Warehousing facilities must be constructed to resist rodent incursions and prevent damp conditions.

Primary Cleaning and Steam Cooking

When raw cashew nuts arrive at the processing unit, they must first undergo cleaning to remove sand, stones, stalks, and dust. This is performed using mechanical raw nut cleaners equipped with vibrating sieves. After cleaning, the nuts are subjected to steam cooking to soften the hard outer shell, which makes shelling easier and reduces kernel breakage. The nuts are loaded into a steam boiler or pressure cooker, where they are steamed at a pressure of four to six kilograms per square centimeter for twenty to thirty minutes. Steaming also helps in releasing the corrosive CNSL from the shell, which is collected as a valuable by-product. The steamed nuts are spread out on a concrete floor to cool and dry for twenty-four hours before shelling. The steam cooking unit requires clean soft water to prevent scale formation inside the boiler chambers. Proper ash removal protocols must be established to keep the steaming zone hygienic.

Shelling and Kernel Separation

Shelling involves cracking the outer shell of the steamed nut to extract the inner kernel. This is one of the most critical stages because maintaining whole kernels is essential, as whole kernels command a much higher price than broken pieces. Shelling can be done manually using foot-operated cracking machines or automatically using mechanical shelling lines. In automatic lines, the cooled nuts are fed into a sizing machine that grades them by thickness, and then they are sent to matching shelling heads where blades slice the shell without damaging the kernel. After cracking, the mixture of shells and kernels passes through shell separators, and any remaining unshelled nuts are returned for reprocessing. Laborers manually separate the kernels from the broken shells using specialized picking tables. The separation tables are fitted with dust hoods to maintain air quality for operators.

Kernel Drying and Humidification

The extracted cashew kernels are covered with a thin, brown seed coat called the testa. To remove this skin without breaking the kernel, the kernels must be dried. They are placed on trays and loaded into hot-air chamber dryers, commonly known as Borma dryers, where they are dried at temperatures between seventy and eighty degrees Celsius for six to eight hours. This drying process reduces the moisture content of the testa, making it dry and brittle. After drying, the kernels are highly fragile and cannot be peeled immediately. They are moved to a humidification or conditioning chamber, where they absorb a controlled amount of moisture for twelve to twenty-four hours. This humidification makes the kernel slightly pliable while keeping the testa brittle, which is necessary to prevent breakage during peeling. The drying room temperature must be regulated continuously using automatic thermostat sensors.

Peeling and Skin Removal

Peeling is the process of removing the paper-like testa from the conditioned cashew kernels. In small-scale units, peeling is done manually by workers using wooden rollers or scrapers to gently peel off the skin. For commercial units, mechanical peeling machines are used. These machines use high-pressure compressed air nozzles inside a rotating drum to blow away the brittle outer skin from the kernels. Mechanical peeling is fast and efficient, but it can result in a higher percentage of broken kernels if the conditioning step was not executed correctly. The peeled kernels are passed through aspiration channels to separate the loose skins, which are sold for tannin extraction. The air compressors supplying pressure to the peeling drum must be fitted with moisture traps and oil filters to keep the air stream clean.

Cashew Grading Standards

After peeling, the kernels must be graded according to size, color, and condition. The Cashew Export Promotion Council of India (CEPCI) defines standard grades that are followed globally. Graders sort the kernels into wholes, splits, and pieces. Whole white kernels are classified by count per pound. W180 (known as the king of cashews, with one hundred and eighty wholes per pound) is the largest and most expensive grade, followed by W240, W320, W450, and W500. W320 is the most widely traded commercial grade due to its balance of size and affordability. Grains that are scorched during drying are graded separately as scorched wholes (SW). Broken kernels are graded as splits (S), butts (B), pieces (P), or baby bits (BB). Proper grading is essential to secure premium wholesale prices. Grading tables must have adequate white lighting to assist operators in visual checks. Size verification cards are placed on walls to help maintain precision.

Vacuum Packaging and Preservation

Cashew kernels contain high levels of unsaturated fats, making them prone to oxidation and rancidity if exposed to air and light. To ensure a shelf life of up to twelve to eighteen months, the graded kernels must be vacuum-packed. They are filled into multi-layer barrier pouches, and the air is evacuated. Before sealing, the bags are flushed with a mixture of carbon dioxide and nitrogen gases. This gas flushing prevents the kernels from sticking together, protects them from physical crushing during transport, and prevents insect infestation. The sealed bags are packed in corrugated fiberboard cartons for distribution. The storage room must be dry, cool, and well-ventilated. The packaging machines must undergo regular leak checks to prevent gas dilution in storage.

Machinery Specifications and Layout

A commercial cashew processing plant requires a range of mechanical units, including a raw nut grader, steam boiler (baby boiler), steam cooker, automatic shelling machines, shell separators, Borma dryer trays, humidification misting fans, air-blast peeling machines, rotary grading tables, and a vacuum packaging machine with gas flushing attachments. The processing line must be laid out in a linear fashion to allow a smooth, single-direction flow of materials and prevent cross-contamination between raw RCN and finished kernels. The power requirement for a medium-sized plant processing two tons of RCN per day ranges from twenty to forty horsepower, which requires a dedicated three-phase connection and an air compressor. The layout should also allocate separate rooms for the peeling and grading divisions.

Power and Labor Requirements

Cashew processing is a highly labor-intensive business. While automatic shelling and peeling machines reduce manual labor, human intervention is still required for sorting unshelled nuts, separating shells from kernels, and grading the final product. A typical unit processing two tons of RCN daily requires thirty to fifty workers, with a high proportion of female workers who excel in precision sorting and grading. Operators must implement ergonomic workstations and provide safety goggles and gloves to workers handling raw nuts to protect them from CNSL residues. Training workers in proper handling techniques is necessary to minimize kernel breakage and maintain high recovery rates. The facility must include clean washrooms, change rooms, and dining areas to ensure worker welfare.

Licensing and Compliance

Compliance with food safety and environmental laws is mandatory for starting a cashew processing unit. Since cashews are food products, the enterprise must obtain an FSSAI license. Micro-units can start with a basic FSSAI registration, while commercial factories require state or central FSSAI licenses based on their processing capacity. Registering the unit on the Udyam MSME portal is necessary to qualify for priority lending, interest subvention, and marketing assistance. The unit must also obtain environmental clearance (Consent to Operate) from the State Pollution Control Board due to boiler smoke emissions and the generation of CNSL waste. Other approvals include a local municipal trade license and a factory inspector certificate. Regular safety drills must be conducted for steam boilers.

PM-FME Subsidy and Loans

The Government of India supports the establishment of food processing units under several credit-linked subsidy schemes. Under the PM-FME scheme, eligible processors can receive a capital subsidy of thirty-five percent of the project cost, up to ten lakh rupees. For larger projects, the Agriculture Infrastructure Fund (AIF) offers interest subventions. Bank financing can be secured through term loans and working capital facilities under the Mudra scheme for micro-enterprises or nationalized bank schemes. All subsidy guidelines, interest subventions, and loan approval parameters are indicative, competitive, credit-linked, and subject to banking guidelines. Entrepreneurs must verify current guidelines on official portals. Checking with local district industry centers can help clarify application steps.

Indicative Project Economics

The total capital investment for a medium-scale cashew processing unit ranges from twenty-five lakh to sixty lakh rupees, covering civil works, machinery, and utilities. The working capital requirement is high because RCN must be purchased in bulk during the harvest season to sustain year-round processing. The kernel recovery rate from raw RCN is indicative and typically ranges from twenty-two to twenty-five percent of the total RCN weight, with shells accounting for seventy percent, and CNSL accounting for five to eight percent. The financial viability depends heavily on the price gap between raw imports and finished kernel grades, and entrepreneurs should consult financial advisors before starting. Sourcing costs can fluctuate depending on global harvest trends.

Marketing and Value Addition

Peeled cashew kernels can be sold in bulk to wholesale food dealers, sweet manufactures, and export houses. Processors can also invest in value-addition equipment, such as roasting machines and seasoning drums, to produce flavored cashews (roasted, salted, spiced, or chocolate-coated). Selling branded, retail-ready pouches of flavored cashews yields significantly higher margins than bulk kernel trading. The by-product CNSL can be sold to chemical industries for manufacturing paints, varnishes, brake linings, and resins, providing an additional source of revenue. Developing a strong brand and establishing partnerships with major e-commerce platforms can help expand the market reach.

Quality Standards and Testing

To access international markets, processors must implement strict quality management systems such as HACCP and ISO 22000. Raw cashew nut batches must be inspected for moisture and internal molds before roasting. The sorting hall must be kept clean, dust-free, and pest-controlled. Regular testing of the finished kernels for microbiological safety, moisture levels, and peroxide values is necessary to comply with buyer specifications. Workers must follow strict personal hygiene protocols, including washing hands and wearing sanitised aprons. Establishing a small in-house quality control laboratory helps monitor these parameters daily, ensuring that no sub-standard batches leave the facility. Testing records must be preserved for future inspections.

Support and Training Resources

Technical training, project blueprints, and market statistics can be obtained from the National Research Centre for Cashew (NRCC) in Puttur, Karnataka, and the Cashew Export Promotion Council of India (CEPCI) in Kollam, Kerala. These organizations conduct regular training programs on processing technology, quality control, and export regulations. Local Krishi Vigyan Kendras (KVKs) also provide assistance with project report preparation and business incubation. Entrepreneurs should consult experienced food processing engineers to design the plant layout, ensuring safety and efficiency. Agricultural figures, yields, and fertilizer details should be verified with Soil Health Cards and local extension offices. Seeking guidance from university extension blocks ensures access to recent storage technologies.

To calculate potential returns on your processing setup and check eligibility for government schemes, you can use the interactive tools and calculators provided for agricultural businesses.

वारंवार विचारले जाणारे प्रश्न

What is the average kernel recovery rate from raw cashew nuts?

The recovery rate is indicative and typically ranges from twenty-two to twenty-five percent of the total RCN weight, depending on the outturn and nut quality.

Why must raw cashew nuts be steam cooked before shelling?

Steaming softens the hard outer shell and helps release the corrosive cashew nut shell liquid, making shelling easier and reducing kernel breakage.

What is W320 grade in cashew classification?

W320 stands for whole white kernels that count three hundred and twenty nuts per pound, which is the most widely traded commercial grade.

Is an FSSAI license required for a cashew processing unit?

Yes, commercial cashew processing units must obtain FSSAI registration for micro-scale, and state or central licenses for larger capacities.

What is Borma drying in cashew processing?

Borma drying is hot-air drying of peeled kernels at seventy to eighty degrees Celsius for six to eight hours to make the outer skin brittle for easy peeling.

Can I get a PM-FME subsidy for cashew processing?

Yes, eligible units can receive a credit-linked subsidy of thirty-five percent of the project cost, up to ten lakh rupees under the PM-FME scheme. Terms are indicative.

What is CNSL and how is it used?

Cashew Nut Shell Liquid is a corrosive oil present in the shell. It is collected as a by-product and sold to industries for paints, resins, and brake pads.

Why are cashew kernels vacuum packed?

Vacuum packaging prevents fat oxidation and rancidity, protects kernels from moisture, and extends their shelf life up to eighteen months.

Do I need pollution control board clearance for a cashew unit?

Yes, you must obtain a Consent to Operate from the State Pollution Control Board to manage boiler emissions and CNSL liquid waste.

What are splits and pieces in cashew grading?

Splits are kernels broken longitudinally into two halves, while pieces are smaller fragments, both sold at lower prices than whole kernels.

How much power is required for a commercial cashew processing plant?

A medium-scale plant processing two tons of RCN daily typically requires twenty to forty horsepower of three-phase electrical power.

Is MSME registration required for a cashew unit?

Yes, registering on the Udyam MSME portal is essential to qualify for interest subvention, subsidies, and priority sector bank lending.

What is the conditioning or humidification stage?

After drying, kernels are kept in a high-humidity chamber to absorb minor moisture, making the kernels pliable to prevent breakage during peeling.

Can I finance a cashew processing plant using a Mudra loan?

Yes, Mudra loans up to ten lakh rupees are available for financing small-scale cashew processing machinery, subject to bank guidelines.

Where can I receive training on commercial cashew processing?

Training is provided by the National Research Centre for Cashew in Puttur, Karnataka, and the CEPCI laboratory in Kollam, Kerala.