How to Produce High-Quality Soybean Oil?: Step-by-Step Refining Process Guide

When customers ask me about soybean oil production, one of the most common questions is: “Is extraction enough, or do we still need refining?”

Your process will stop at crude oil stage if you stop at extraction alone. This means the oil is still unrefined, containing impurities, odor, and pigments, and is not yet suitable for direct edible use.

In real industrial operation, refining is just as important as extraction. Even if you achieve a high oil yield during extraction, the crude oil still needs proper refining to become a stable, safe, and high-quality edible product.

In this article, I’ll walk through the soybean oil refining process step by step, and share how I usually help plants understand which refining configuration best fits their production goals.

Understanding the Purpose of Refining

Before going into the process, I always remind operators of one key point:
Crude soybean oil is not yet ready for consumption.

It typically contains:

🔸Phospholipids (gums) 

🔸Free fatty acids 

🔸Pigments 

🔸Moisture and trace impurities 

So refining is not just an optional upgrade—it is essential for:

🔸Improving oil stability 

🔸Enhancing taste and appearance 

🔸Meeting food safety standards

1. Degumming – Removing Gums and Phospholipids

The first step I usually focus on is degumming.

In this stage, water or acid is added to hydrate phospholipids so they can be separated from the oil.

What I aim for here is simple:

🔸Reduce impurities that affect stability 

🔸Prepare oil for further refining steps 

🔸Improve overall refining efficiency 

There are different degumming methods depending on plant design, but the goal remains the same—cleaning up the crude oil at an early stage.

2. Neutralization – Reducing Free Fatty Acids

Next comes neutralization, which is one of the most critical steps in refining.
Here, alkali is used to react with free fatty acids, forming soapstock that can be removed.

From my experience, this step directly affects:

🔸Oil taste 

🔸Storage stability 

🔸Final refining yield 

If neutralization is not well controlled, you may lose yield or affect downstream quality.

3. Bleaching – Improving Color and Purity

After neutralization, the oil still contains pigments and trace impurities.
So we move into bleaching.

In this step, bleaching earth or activated clay is used to:

🔸Adsorb color pigments 

🔸Remove oxidation products 

🔸Improve clarity and appearance 

I usually explain this stage as “fine polishing” of the oil—where visual and chemical quality is significantly improved.

4. Deodorization – Final Quality Stabilization

Deodorization is the final and most important refining step.

Here, high temperature and vacuum conditions are used to remove:

🔸Odor compounds 

🔸Volatile substances 

🔸Remaining free fatty acids 

This step determines the final quality of the oil in terms of:

🔸Taste neutrality 

🔸Shelf life 

🔸Consumer acceptance 

In modern plants, this stage is also where energy efficiency technologies like heat recovery systems play a key role in reducing operational cost. From my experience working with advanced refining technologies, I’ve seen innovations such as Myande’s variable-temperature deodorization system being developed to minimize the impact of high-temperature processing on oil quality.

This system reduces deodorization heating residence time to less than 30 seconds, with operating vacuum levels reaching 0.5–1.5 mbar, improving deacidification efficiency while shortening high-temperature exposure. 

As a result, the formation of undesirable compounds such as trans fatty acids, 3-MCPD esters, and glycidyl esters is effectively reduced.

In some oil applications, these advanced technologies have enabled “zero trans-fat” performance, with 3-MCPD ester and glycidyl ester levels achieving results better than EU standards, significantly improving overall oil safety and quality.

Understanding Chemical Refining vs. Physical Refining

When I help clients choose refining systems, I usually explain two main approaches:

Chemical Refining

🔸Includes degumming, neutralization, bleaching, deodorization 

🔸Suitable for a wide range of crude oil qualities 

🔸More flexible in industrial applications 

Physical Refining

🔸Removes free fatty acids mainly during deodorization 

🔸More energy efficient in certain cases 

🔸Requires high-quality crude oil input 

Choosing between these depends on raw material quality, plant scale, and production strategy.

If you want a deeper understanding of the differences, you can refer to our Physical Refining vs Chemical Refining: How Do You Choose the Right Process for Edible Oil? 

Automation and Modern Refining Technology

In modern soybean oil plants, refining is no longer a standalone system.

From what I've seen in advanced facilities, automation now plays a key role in:

🔸Precise chemical dosing 

🔸Stable vacuum and temperature control 

🔸Energy recovery optimization 

🔸Continuous production stability 

For example, companies like Myande Group integrate refining systems with advanced process control and energy recovery technologies, helping plants achieve more stable and efficient operations at industrial scale.

In my experience, building an edible oil refinery plant is a major investment, and the choices made at the early planning stage usually have the greatest impact on the project's long-term performance.

The most successful projects I’ve seen are those where attention is not limited to equipment selection alone, but also includes overall process design, production efficiency, product quality targets, and cooperation with reliable technology partners.

When these factors are properly considered from the start, the refinery is far more likely to achieve stable operation, consistent product quality, and strong long-term profitability.