Press rapeseed oil yourself

When is the right time – and what is really important?


If you want to press rapeseed oil yourself, you have a question that decides on the yield and quality: When is the seed really ripe – and what conditions must be met when pressing? This guide will give you practical answers.

1. Harvest time: the most important factor for high-quality rapeseed oil

When is rapeseed ready for harvest?

Rape should be harvested when the moisture content of the seed has dropped to 8-10%. This usually corresponds to the stage in which the pods have taken on a brown-yellowish color and a rattling can be heard when the plant is gently shaken.

  • Pod color: brown-yellow to dark brown
  • Grain color: dark brown to black
  • Moisture content: below 10% (measurement with moisture meter recommended)
  • Period: Typically late July to mid-August in Germany

What happens when the harvest is too early or late?

Early harvesting leads to increased chlorophyll content – the oil becomes greenish and bitter. Harvesting too late increases the risk of pod bursts and thus harvest losses, and the risk of fungal infestation increases.

2. Seed preparation: This is how the optimal pressing process succeeds

Drying and Cleaning

Before putting rapeseed in the oil press, the seed should be cleaned and dried to a maximum moisture content of 8%. Moist seeds lead to reduced yield, blockages in the screw and increased wear on the pressing cylinder and nozzle.

  • Cleaning: Removal of dirt, straw and foreign bodies
  • Storage before pressing: dry, ventilated, temperature 15-20 °C
  • Measure Humidity: Ideal 6-8%

preheating of the seed

Lightly preheated seed (30-40 °C) flows more evenly into the press and improves the oil yield.

3. Temperature management in pressing – the key to quality

What doescold pressed?

For oils other than olive oil, there are hardly any specific EU legal definitions for “cold pressed”. This is a generally recognized method of manufacturing without the supply of heat (often mechanically below 40 °C), which is not as strictly controlled as with olive oil.

How do you regulate the temperature?

The temperature can be controlled via the pressing speed, the nozzle diameter and – in advanced machines such as the Oleo P 20 or Oleo P 40 – via integrated temperature control systems.

4. Optimize yield – tried and tested tips

Typical yields in rapeseed

350-430 ml of oil can be pressed from 1 kg of rapeseed, depending on the machine setting and seed quality. The press cake still contains about 12-18% residual oil and can be used as a high-quality animal feed or fertilizer.

  • Optimal Yield: 380-420 ml/kg Seed
  • Press cake residual oil content: 12-18%
  • Pressing speed: slower = more pressure = higher yield (but higher temperature)

5. Maintenance: What is often overlooked

Check wear parts regularly

The most common problems with rapeseed oil pressing are caused by worn screws, knocked-out cylinders or clogged nozzles. Regular control significantly extends the life of the machine and ensures consistent quality.

  • Screw (press spindle): check for material loss and grooves
  • Press cylinder: pay attention to cracks and even wear
  • Nozzle: Clean after each pressing layer

conclusion

Pressing rapeseed oil yourself is a worthwhile task – provided that the harvest, drying, temperature and machine care are right. With the right know-how and a reliable oil press, you can produce high-quality, cold-pressed rapeseed oil in consistent quality.