Peanut and sesame are two of the most widely cultivated oilseeds in the world, valued for their high oil content, rich nutrition, and stable market demand. For oil mills and small-scale oil producers, even a small improvement in oil yield can translate into significant profit growth. However, many operators struggle with low oil output, high residual oil in the cake, and unstable pressing efficiency due to poor raw material handling, insufficient pre-press preparation, and incorrect machine settings.
This guide shares 6 practical, field-tested methods to increase peanut and sesame oil yield, covering raw material selection, moisture control, roasting, pressing parameters, secondary extraction, and equipment maintenance. These tips are suitable for both screw oil presses and hydraulic oil presses, helping you improve oil extraction rate without heavy investment.
1. Select High-Oil Varieties and Screen Raw Materials Carefully
Oil yield starts with the inherent oil content of the raw material. Different peanut and sesame varieties have large differences in oil content, which directly determines the upper limit of oil production.
For peanuts, choose full, uniform, shelled kernels that are free from mildew, shriveling, and damage. High-quality peanut kernels generally contain 48%–52% oil, while poor-quality or shrunken kernels may only contain 38%–42%. For sesame, white sesame usually performs better than black sesame in oil yield, and premium white sesame can reach 50%–53% oil content.
Before pressing, screen the raw materials thoroughly to remove stones, soil, moldy grains, broken particles, and other impurities. Impurities take up space in the press chamber, block clearances, and reduce pressing pressure, which lowers oil yield and may also affect crude oil quality. Simply removing low-quality seeds can increase overall oil yield by 2%–3%.
2. Control Raw Material Moisture for Better Oil Separation
Moisture content is one of the most critical factors affecting oil yield, and it is also one of the most commonly overlooked steps. Both too high and too low moisture can reduce extraction efficiency.
The recommended moisture range before pressing is:
- Peanut kernels: 5%–7%
- Sesame: 6%–8%
If the moisture is too high, the material tends to become sticky during pressing, forming lumps and blocking the press chamber. This prevents oil from separating fully and leaves more residual oil in the cake. If the moisture is too low, the seeds become hard and dry, which can generate extra friction heat during pressing, cause oil volatilization, and lead to dry cake adhesion.
It is best to test moisture with a simple moisture meter. If the raw material is too wet, use natural air drying or low-temperature drying to bring it into the target range. Proper moisture adjustment alone can help stabilize oil yield by 3%–5%.
3. Optimize Roasting Temperature and Time
Proper roasting softens seed tissues, activates oil components, reduces oil viscosity, and helps oil flow out more easily. For most hot-pressing operations, roasting is an essential step for improving oil yield.
Recommended roasting parameters:
- Peanuts: 120–160℃, 10–25 minutes
- Sesame: 110–150℃, 8–20 minutes
Peanuts can tolerate slightly higher temperatures, but over-roasting should still be avoided. Sesame burns easily, so low-temperature and slow roasting is usually better. Uneven heating may cause some seeds to be under-roasted while others are burnt, resulting in unstable oil output and wasted material.
4. Use Hot Pressing with Appropriate Pressure and Timing
Cold pressing can retain more natural nutrients, but it usually results in lower oil yield. Hot pressing is the more practical choice for maximizing oil output in commercial production. After roasting, press the materials while they are still hot, and match the pressure and holding time to the material type.
General pressing parameters:
- Hydraulic oil press: 55–60 MPa
- Sesame: about 30–40 minutes per batch
- Peanuts: about 25–35 minutes per batch
- Screw oil press: maintain stable feeding speed and rotation speed
- Avoid over-feeding, which causes blockage
- Avoid under-feeding, which leads to insufficient pressure
With proper hot pressing, peanut and sesame oil yield can reach 48%–52% in many well-managed cases, which is 3%–6% higher than typical cold pressing.
5. Re-Press the Oil Cake to Reduce Residual Oil
Even under optimized conditions, the first-pressed cake still contains residual oil. In normal single-pass pressing, peanut cake may retain about 5%–6% oil, and sesame cake about 4%–5% oil.
One effective way to improve total oil yield is secondary pressing. After the first press, the oil cake can be crushed, adjusted slightly for moisture, and then re-pressed at a lower temperature. This process can extract an additional 2%–4% oil without obvious negative impact on oil quality.
Secondary pressing is especially useful for medium and large oil mills that want to get more value from their raw materials.
6. Maintain the Oil Press Regularly for Stable Performance
Oil yield can also drop when the machine is not well maintained. Worn screws, clogged filters, leftover cake in the press chamber, and aging parts can all reduce pressing efficiency over time.
Simple maintenance tips:
- Clean the press chamber and remove residual cake after daily operation
- Check the screw shaft, pressing barrel, and filter screens regularly
- Replace worn parts in time to maintain stable pressure
- Keep the oil outlet and filter system smooth
Good equipment management helps avoid unexpected yield loss and keeps oil extraction performance stable batch after batch.
Reference Oil Yield Data
When the above methods are used together, peanut and sesame oil yield can reach a good industry level:
- Peanut kernel hot pressing: 48%–52%
- Sesame hot pressing: 48%–52%
- Overall oil yield improvement compared with traditional pressing: 8%–15%
Conclusion
Increasing peanut and sesame oil yield does not always require expensive equipment upgrades. The most practical improvements come from standardized raw material processing, accurate moisture control, optimized roasting, proper hot-pressing parameters, secondary extraction, and routine equipment maintenance.
By following these steps, oil producers can reduce raw material waste, improve oil extraction efficiency, and achieve more stable and profitable production.
If you need customized pressing parameters for your specific oil press model, feel free to contact us for professional technical guidance.