This is the most common and economical extraction method. There are three main methods, listed from lowest to highest quality and cost:

1. Hot Pressing

Process: Flaxseeds are first steamed and roasted at high temperatures, then physically pressed using a screw press.

Characteristics:

High oil yield (up to 85% or more), full utilization of oilseeds.

High temperature destroys anti-nutritional factors in the seeds, but also leads to the oxidation and loss of some nutrients (such as α-linolenic acid), resulting in a darker color and lower smoke point.

The oil may contain more impurities and requires refining.

Rich flavor, with a typical "flaxseed oil taste".

Main uses: Industrial oil (paints, inks), animal feed, or refined for use as ordinary edible oil.

2. Cold Pressing

Process: Flaxseeds are directly pressed using a screw press at a low temperature (usually <60°C).

Characteristics:

Retains the most natural nutrients, especially heat-sensitive alpha-linolenic acid, vitamins, and lignans. Highest quality.

Lower oil yield (approximately 30-35%), higher cost.

Clear oil, golden in color, with a natural nutty aroma.

Poor stability; requires storage away from light and at low temperatures.

Main uses: High-end health care oil, nutritional supplement, high-grade cosmetic base oil.

3. Solvent Extraction Method

Process: The pressed cake or directly crushed seeds are soaked in a food-grade organic solvent (commonly n-hexane) to dissolve and extract the remaining oil. The solvent is then recovered by distillation.

Characteristics:

Highest oil yield (up to 99% or more), best economic benefits.

The extracted oil must undergo rigorous refining (degumming, deacidification, decolorization, deodorization) to remove solvent residues and impurities.

Refining processes result in the loss of some natural nutrients and flavor.

Main uses: The primary production method for most refined flaxseed oil on the market is for general cooking.

Modern combined process: Pre-pressing-extraction method. To balance efficiency and oil quality, cold pressing or cryogenic pressing is often used first to obtain high-quality "first-press oil." The resulting cake is then solvent-extracted to obtain solvent-extracted oil (typically used for refining or industrial applications).