What is the cold pressing process?

What is the cold pressing process?

Cold pressing refers to pressing oil at low temperature, usually not higher than 60 degrees Celsius, so that more nutrients and natural flavors can be retained.
Advantages include nutrition retention, natural cold pressing, and suitable for high-oil crops such as peanuts, sesame, walnuts, and flax seeds. The nutrition is retained intact, the oil is natural, suitable for cold salad/direct consumption, no chemical residue, and high safety.

Characteristics of cold pressing process

Low temperature protects nutrition
Avoids the loss of heat-sensitive components such as oil oxidation, fatty acid decomposition, and vitamin E caused by high temperature.
Natural and additive-free
Extract oil only through physical pressure, without chemical solvents (such as No. 6 light gasoline) or high-temperature refining.
Retain flavor
Suitable for cold-pressed peanut oil, sesame oil, olive oil and other oil crops that need to retain a unique aroma.
Oil yield
Due to the lack of high-temperature softening of oil, the oil yield of cold pressing is usually 10%~20% lower than that of hot pressing.

Walnut oil cold pressing method

Raw material screening: Select walnuts with full grains, no deterioration, and no pests as raw materials to ensure the quality of walnut oil.
Cleaning and drying: Wash the selected walnuts, remove surface impurities, and then dry them to reduce the moisture content of the walnuts to a suitable range, generally 5% - 8%, for the subsequent pressing process.
Shelling and crushing: Use special shelling equipment to remove the walnut shells, and then crush the walnut kernels into appropriate particle sizes, which can increase the exposure area of ​​​​the oil and improve the oil yield.
Cold pressing: Put the crushed walnut kernels into a cold press for pressing. The cold press applies pressure to the walnut kernels through the rotation of the spiral shaft, so that the oil is squeezed out of the walnut kernels. During the pressing process, the pressing temperature and pressure must be controlled. Generally, the temperature does not exceed 60℃, and the pressure is adjusted according to the actual situation to ensure the quality and oil yield of the oil.
Filtration and separation: The squeezed walnut oil contains some impurities and moisture, which needs to be processed by filtering and separation equipment. Common filtering methods include filter pressing and centrifugal filtration to remove impurities and moisture to obtain clear and transparent walnut oil.
Packaging and storage: Put the filtered walnut oil into a clean, sealed container, store it away from light and at low temperature to maintain the quality and stability of the walnut oil.