Olive oil is more than just a kitchen staple—it’s liquid gold that embodies centuries of tradition, culture, and health benefits. For thousands of years, Mediterranean civilizations have prized it not only as food, but also as medicine and a symbol of purity. Today, olive oil is one of the most valued products in the global culinary world. From gourmet chefs to health-conscious households, its demand continues to grow.
The quality, flavor, and shelf life of olive oil depend not only on how it is harvested and produced but also on how it is filtered. While the process may appear simple—harvest, press, filter, bottle—every stage requires precision. Even small variations, such as harvest timing or filtration technology, can significantly alter the final product. For premium extra virgin olive oil (EVOO), which represents the highest quality standard, small errors can reduce both value and shelf life.
Harvest and Production Timeline
Picking and Cleaning: Damaged or spoiled olives are discarded, ensuring only high-quality fruit is used.
Pressing and Grinding: Olives are crushed into a paste and mixed for 20–30 minutes before oil extraction.
Filtration: Removes plant tissue, water, and fine particles that compromise stability and flavor. Stainless steel housings with PP liquid filter bags or cellulose depth filter sheets are commonly used.
Separation: A high-speed centrifuge eliminates residual water to yield pure oil.
Bottling: Oil is stored in dark, airtight containers to preserve freshness.
Filtration Technology
Filter Media and Mechanism
Made from pure cellulose fibers, sometimes enhanced with mineral components such as diatomaceous earth.
Mechanisms include:
• Asymmetric pore structure: Retains larger particles on the surface and finer ones within the sheet.
• Mechanical retention: Traps particles and microorganisms.
• Adsorptive retention: Captures finer impurities within the fiber matrix.
Advantages of Gentle Filtration
• Preserves natural colors, flavors, and aromas.
• Removes nearly 100% of particles and water.
• Provides strong microbiological safety.
• Minimal oil loss with drip-free operation.
• Made from natural, biodegradable materials.
• Improves efficiency by up to 30%, saving both time and cost.
Great Wall Filtration Depth Filter Sheets
Great Wall filter sheets are manufactured from high-purity cellulose fibers without added minerals. This ensures:
• Preservation of authentic taste, aroma, and color.
• Excellent separation of water and solids.
• Higher yield, as less oil is absorbed by the sheet.
• Reliable performance even with early-harvest EVOO.
Key Benefits
• Maximization – Prevents haze, extending shelf life.
• Preservation – Maintains natural sensory qualities.
• Reduction – Minimizes oil loss, improving yield.
Recommended Types
High purity cellulose
It does not add any mineral filter AIDS, has extremely high cellulose purity, can adapt to different chemical environments such as acids and alkalis, greatly reduces the risk of metal ion precipitation, and can well retain the color and aroma of the filtered liquid.
Standard
Depth filter sheet with high-quality filter AIDS features high stability, wide application range, high inner strength, ease of use, strong endurance and high safety.
High performance
This filter sheet is specially designed for filtration tasks with high filtration difficulty, high liquid viscosity, and high solid content, and it has a high filtration efficiency. It has a strong adsorption capacity and an extremely high ability to retain microorganisms and bacteria.
Modules
The membrane stack Modules of Great Wall can contain different types of cardboard inside. When paired with membrane stack filters, they are easy to operate, isolated from the external environment, and more hygienic and safe.
Ideal Filtration System
The Great Wall filtration system offers flexibility and efficiency:
Configurable as sheet filter, precoating filter, or combination filter.
• Automatic hydraulic tightening for minimal product loss.
• Ergonomic, easy-to-clean design.
• Stainless steel construction with smooth, hygienic surfaces.
Conclusion
Olive oil production is both an art and a science. From carefully timed harvesting to pressing, extraction, and filtration, every step shapes the final product. Among these, filtration is the guardian of quality—preserving aroma, taste, and stability while extending shelf life.
Modern filtration systems, particularly those using Great Wall depth filter sheets, have transformed production by combining efficiency with preservation. Producers can achieve maximum yield without sacrificing the delicate characteristics that define premium olive oil. Paired with proper bottling and storage, filtration ensures that consumers receive nothing less than exceptional “liquid gold.”
As global demand for EVOO continues to rise, producers who refine their filtration process will remain industry leaders. Filtration isn’t just a final step—it’s the cornerstone of excellence in olive oil production.
FAQs
1. Why is filtration so important for extra virgin olive oil?
It removes particles and water that cause spoilage, ensuring clarity, stability, and a longer shelf life.
2. What happens if olive oil is not properly filtered?
Unfiltered oil can develop haze, off-flavors, and spoil more quickly due to microbial activity and enzymes.
3. Is unfiltered olive oil healthier?
Not necessarily. While it may contain more particles, these degrade rapidly, leading to fermentation and loss of quality. Filtered EVOO is more stable and reliable.
4. Which filtration method is best for small producers?
Depth filter sheets, such as Great Wall filters, are ideal—highly efficient, yield-preserving, and gentle on flavor.
5. How does storage affect olive oil quality?
Even filtered oil degrades if exposed to light, heat, or oxygen. Storing in dark glass bottles at cool temperatures ensures freshness and longevity.
