A Beginner's Guide to Sunflower Oil Production: Key Differences Between Cold and Hot Pressing

A Beginner's Guide to Sunflower Oil Production: Key Differences Between Cold and Hot Pressing

Sunflower oil is produced from sunflower seeds by mechanical pressing or through additional processing steps. For new producers, one of the main questions is: which method to choose— cold or hot pressing?

The difference isn't just a matter of temperature. The technology affects oil yield, the properties of the raw materials, flavor, color, subsequent purification, and production costs.

What Is Cold-Pressed Sunflower Oil?

Cold pressing (cold extraction) — is the mechanical extraction of oil without the deliberate heating of the raw material. According to the international standard Codex Alimentarius CXS 19-1981, cold-pressed oils are produced using mechanical methods without the application of heat; processes such as settling, filtration, and centrifugation are permitted.

In practice, the seeds are cleaned of impurities, graded if necessary, and fed into a screw press. The oil is separated from the cake by pressure.

The main advantage is a gentler processing method. When the settings are chosen correctly, it is possible to preserve the seeds’ characteristic flavor and aroma and reduce the impact of high temperatures on the oil.

However, cold pressing does not automatically mean «oil without heating»: due to friction in the screw press, the temperature of the product may rise. Studies show that the actual temperature of the oil at the outlet depends on the press design, screw speed, moisture content, and seed composition. In one recent study, the oil temperature was approximately 44–70 °C.

What Is Hot Pressing?

Hot Pressing involves pre-conditioning or heating the seeds before pressing. Heating breaks down the seed structure and promotes more intensive oil extraction.

This is particularly important for industrial production, since the main objective is not only to preserve the product’s natural characteristics but also to achieve a consistent oil yield and high equipment productivity.

After pressing, the resulting oil typically undergoes additional purification processes, depending on the product's intended use.

Cold-Pressed and Hot-Pressed: What's the Difference?

Indicator	Cold pressing	Hot Pressing
Effects of Heat	Minimum	Significant
Oil output	Usually lower	Usually higher
Taste and aroma	More characteristic of seeds	More pronounced after heating
Performance	Below	Above
Raw Material Requirements	Higher	More flexible
Positioning	Natural, premium	Mass-market and industrial

It is important to understand that There is no fixed, universal oil yield for all sunflower seed batches.. It depends on the oil content, moisture content, variety, hull content, preparation of the raw material, and press parameters.

A recent study on cold pressing revealed a significant difference between sunflower varieties: the oil extraction efficiency for oil-producing hybrids was 41,63–75,61%, whereas in confectionery hybrids — 20,10–48,40%. This confirms just how much the characteristics of the raw materials affect the outcome of the pressing process.

Why Seed Quality Is Crucial

Before production, it is necessary to check moisture content, oil content, hull content, impurities, and mechanical damage to the seeds.

For example, studies show that the content of husks and impurities can significantly affect the press's productivity and the amount of oil produced.

Therefore, the same press can produce completely different results when processing different batches of seeds.

For a sunflower oil producer, it is especially important to select not only the right equipment but also the appropriate raw materials.

Which method should a beginner manufacturer choose?

If the main goal is — Premium natural oil, small-scale production, and a focus on flavor characteristics, cold pressing may be a more suitable option.

If, on the other hand, the priority is High productivity, consistent output, and industrial-scale operations, hot pressing allows for more efficient use of oilseeds.

That said, cold pressing cannot always be considered «better,» nor can hot pressing always be considered «worse.» These are two different processing strategies.

According to Codex Alimentarius CXS 210-1999, sunflower oil is classified as a standardized vegetable oil, and the requirements for its composition and quality must be evaluated in accordance with the established standard.

Conclusion

For a start-up, the choice of technology should be based on seed quality, required oil yield, equipment capacity, and target market.

Cold pressing is geared toward gentler processing and a focus on natural products, whereas hot pressing is better suited for high-throughput operations. In both cases, the quality of the sunflower seeds remains one of the key factors in the overall efficiency of production.

Sources: FAO/WHO Codex Alimentarius, CXS 19-1981 and CXS 210-1999; scientific studies on the effectiveness of cold-pressing sunflower seeds.