Walnut oil is a precious natural edible vegetable oil. It is rich in unsaturated fatty acids and alpha-linolenic acid, an essential fatty acid that the human body cannot produce on its own and which benefits human health greatly. Light and easy to absorb, it retains the natural nutrients of walnuts. As a high-end specialty oil, walnut oil has outstanding nutritional advantages, versatile applications and promising market value and consumption potential.
Production process:
- Raw Material Inspection and Storage
Test walnut moisture and mould rate, select intact kernels for production. Quality raw materials guarantee good crude oil and oil cake. The warehouse should be dry, ventilated and protected from sunlight to maintain raw material quality.
- Shelling and Kernel-shell separation
Walnuts in shell enter a combined sheller-separator that cracks, winnows and screens in one pass. Shell is light and kernel is heavy, so the air stream carries shell away, the screens grade kernels by size. Whole walnut kernels and broken kernels exit from two separate outlets of the machine.
Shells are not waste — they sell to activated-carbon plants or burn as boiler fuel, and that income belongs in the costing.
- Kernel cleaning
The pellicle carries tannins. Keep it and the oil comes out darker with a fuller flavour, which suits a nut-forward product. For a pale, mild premium oil, add a de-pellicling pass before pressing: colour lightens, astringency drops, and the cost is one extra operation plus some kernel loss.
- Hydraulic pressing
The kernels are loaded into filter cloths and placed into the hydraulic oil press. Simply turn on the switch; pressure is transmitted by hydraulic oil with staged pressurization: low pressure for air venting, medium pressure for oil extraction, high pressure for pressure holding..
The hydraulic press generates no frictional heat during operation. The pressing temperature can be stably kept below 60 °C, protecting the heat-sensitive components of walnut oil.
The single-pass oil yield is 40%–55% (based on in-shell walnuts), with residual oil in the cake at approximately 8%. It delivers stable pressure and intact oil cakes, achieving thorough pressing even for high-oil raw materials.
- Filtration
Crude oil from hydraulic pressing contains relatively few impurities. If higher oil quality is required, a plate and frame filter press can be equipped. The plate-and-frame filter adopts multi-layer filter cloth with high mesh count and fine pores. It can stably capture tiny solid residues in the oil. Oil after filtration is clear and transparent with no visible impurities, improving oil appearanc, storage stability and price.
- Cake
The walnut oil cake obtained after pressing has a protein content of over 35%. It can be sold as a food ingredient or high-quality feed at a better price than ordinary oil cake, and the revenue can be counted towards cost recovery.
- Packaging and storage
Dark glass or opaque containers, sealed, nitrogen-flushed where possible, stored cool and away from light. Too many polyunsaturated fatty acids: light and oxygen push it towards rancidity.
Why This Process Matters
Each step — from cleaning to filtration — directly affects oil quality, yield, and shelf life. Proper blanching prevents rancidity. Controlled drying ensures efficient pressing. Clean raw material means cleaner oil.
As demand for sustainable oils grows, BSF oil production offers a practical solution: turning raw larvae into a valuable, high-demand product.
Ruian Every Machinery (MCRAYONE) is located in Zhejiang province, China. Our annual production capacity of oil press machines and related machines is around 10,000 sets. These machines have sold to all over the world, such as South Africa, Nigeria, America, India and so on. Thanks to our experience in the oil press industry (more than 40 years ), we know the demands and best-selling models of each market, so we can provide the most suitable machines to our customers.
We have an experienced engineer team, a professional Research and Design department, and a perfect Quality Control System. All the parts are made by our own factory and the quality can be guaranteed. In addition, we provide a quality warranty for one year.
Our business involves in small-sized oil pressing series, oil engineering designing, equipment manufacturing and installing, project contracting, technical service and so on. Moreover, we have important partnerships with many large Chinese companies, such as China Oil and Food Import and Export Corporation. We are their designated foreign trade exporter and their supplier for small oil presses.
Our goal is to establish a long-term relationships with our customers, based on providing quality machines at a reasonable cost and maximize the customer returns with comprehensive service.
In the course of our company’s decades of development, we have obtained multiple official certificates, such as :
- ISO-9001 international quality system certification
- CE certificate
- China’s AAA credit enterprises
- Certification for honoring contracts and keeping promises
- Certificate of Integrity management demonstration unit
- Certificate of Quality Service Integrity Unit
- Enterprise Credit Rating Certificate
Our company has grown into one of the leading oil press manufacturers in China, and our popularity has spread abroad. We welcoming all kinds of orders.
