Refined olive oil is olive oil that has been chemically and physically processed to remove defects, flavor, aroma and color. It is cheaper than extra virgin olive oil and widely used in the food industry and home kitchens — especially for frying and baking. But what exactly happens to olive oil during refining, and what does it mean for your health?
What Is Refined Olive Oil?
Refined vs Unrefined Olive Oil
Refined olive oil is olive oil that has undergone a chemical and physical refining process. Unlike extra virgin olive oil, which is only mechanically pressed, refined olive oil is processed to remove all defects, flavor, aroma and color.
The raw material is typically lampante-grade olive oil — virgin oil that doesn't meet extra virgin or virgin standards due to sensory defects or excessive acidity. The goal of refining is to make this "unsuitable" oil fit for consumption.
Why Is Olive Oil Refined?
Refining is necessary to correct low-quality olive oil — removing sensory defects (musty, muddy, vinegary flavors), lowering acidity, removing contaminants and standardizing quality. Without refining, a large portion of the olive harvest would go to waste.
The Refining Process Step by Step
The olive oil refining process consists of five main steps, each removing specific compounds:
| Step | Process | Temperature | Removed |
|---|---|---|---|
| 1. Degumming | Hot water + centrifugation | 70–90°C | Phospholipids, polyphenols |
| 2. Neutralization | Sodium hydroxide (NaOH) | 60–80°C | Free fatty acids → soaps |
| 3. Bleaching | Activated carbon / bleaching earth | ~100°C | Pigments, metals, soap residues |
| 4. Deodorization | Steam refining under vacuum | 150–260°C | Volatile compounds, aroma, flavor |
| 5. Winterization | Rapid cooling + filtration | 0–5°C | Waxes, solid particles |
1. Degumming (Water Treatment)
In the first step, the oil is treated with hot water (70–90°C), which separates phospholipids and some polyphenols. These are then removed by centrifuge. This is the mildest refining step, but the oil already loses a significant portion of its polyphenols here.
2. Neutralization
A sodium hydroxide (NaOH) solution is added to neutralize free fatty acids — converting them into soap particles that are separated by centrifuge. This step brings acidity below 0.3%.
3. Bleaching
Activated carbon or bleaching earth is added at ~100°C to remove pigments (chlorophyll, carotenoids), metal residues and soap remnants. The oil turns from green to pale yellow or nearly colorless.
4. Deodorization
The most intensive step: steam refining under vacuum at 150–260°C removes all volatile compounds — aroma, flavor and the last aromatic compounds. The result is a completely neutral, flavorless and odorless oil.
5. Winterization
The oil is rapidly cooled to 0–5°C to solidify waxes and other high-melting-point substances, which are then filtered out. This ensures the oil remains clear and transparent when stored in cool conditions.
What Refined Olive Oil Loses
Polyphenols and Antioxidants
The biggest loss is in polyphenols — refined olive oil typically contains less than 10 mg/kg of polyphenols, compared to extra virgin olive oil's 150–400 mg/kg. That's over 90% lost. Oleocanthal, hydroxytyrosol and oleuropein — all health-beneficial compounds — are virtually eliminated.
Vitamins and Bioactive Compounds
Vitamin E (tocopherols) decreases by 30–50% during refining. Vitamin K also drops significantly. Chlorophyll is completely removed during bleaching, which also means a loss of carotenoids.
Flavor and Aroma
Refined olive oil is completely neutral in taste and smell — lacking the fruitiness, bitterness and pungency that characterize quality extra virgin olive oil. Deodorization removes all aromatic compounds.
What Refined Olive Oil Retains
Fatty Acid Composition
The good news about refining: the oil's glyceridic structure — its fatty acid composition — remains essentially the same. Oleic acid (omega-9) still makes up 70–80% and monounsaturated fat content is ~85% — the same as in extra virgin olive oil. This means the heart-healthy fatty acids are preserved.
Higher Smoke Point
Refined olive oil has a smoke point of ~210°C (410°F), significantly higher than extra virgin olive oil's 160–190°C. This makes refined olive oil more suitable for high-temperature frying.
When to Use Refined Olive Oil
Deep Frying and High Heat
Refined olive oil's higher smoke point (~210°C) makes it a good choice for deep frying and high-heat pan frying. Since the flavor is neutral, it won't affect the taste of your food either.
Baking and Neutral Flavor
When a recipe calls for a neutral oil that won't overpower other ingredients — such as cakes, pies or light baking — refined olive oil is a sensible choice. It works similarly to regular vegetable oil but contains more monounsaturated fatty acids.
Budget Considerations
Refined olive oil typically costs €5–10 per liter, significantly less than quality extra virgin olive oil (€15–40/L). If you use large amounts of oil for frying, the refined variety is easier on the wallet.
Refined vs Extra Virgin Olive Oil – Comparison
| Property | Refined Olive Oil | Extra Virgin Olive Oil |
|---|---|---|
| Flavor | Neutral, flavorless | Fruity, bitter, pungent |
| Aroma | Odorless | Intense, herbal |
| Color | Pale yellow to colorless | Greenish-gold |
| Smoke point | ~210°C (410°F) | ~160–190°C (320–375°F) |
| Polyphenols | <10 mg/kg | 150–400 mg/kg |
| Acidity | <0.3% | <0.8% |
| Price | Lower (€5–10/L) | Higher (€15–40/L) |
| Best use | Frying, baking | Salads, dips, finishing |
Frequently Asked Questions
What is refined olive oil?
Olive oil that has undergone chemical and physical processing (degumming, neutralization, bleaching, deodorization) to remove defects, aroma, flavor and color. The result is a neutral, flavorless oil with a high smoke point.
Is refined olive oil healthy?
It retains monounsaturated fatty acids that are beneficial for heart health, but loses over 90% of polyphenols and antioxidants. Refined olive oil is healthier than most vegetable oils, but less beneficial than extra virgin olive oil.
Why is refined olive oil cheaper?
It is produced from lower-quality olives or defective oils (lampante) that refining "corrects." Higher production volumes and less stringent quality control keep the price low.
When should I use refined olive oil?
For deep frying (higher smoke point ~210°C), baking (neutral flavor won't dominate), and when budget is limited. For salads, dressings and finishing, extra virgin olive oil is always the better choice.
What is the difference between refined olive oil and "light" olive oil?
"Light" or "extra light" is a marketing term for refined olive oil — it refers to flavor lightness, not lower calories. Both are essentially the same product: refined olive oil with a neutral taste.
Summary
Refined olive oil is not "bad" olive oil — it has its own place in the kitchen. A higher smoke point, neutral flavor and more affordable price make it a practical choice for frying and baking. In terms of health benefits, however, it falls clearly short of extra virgin olive oil: over 90% of polyphenols and a large portion of vitamins are lost during refining. The best strategy? Use refined olive oil for frying and extra virgin olive oil for salads and finishing.