The cleaning procedure is an important practice: it has the same importance of the extraction process.
Any extraction system needs to be cleaned periodically: this period depends on many factors, and All these topics have an impact on the cleaning period:
- Type of the raw material
- Quality of the raw material
- Raw material pre-treatment
- Number of extraction before cleaning
- Use of co-solvent in the extraction process
All along the process the bacteria contamination is very low: during the extraction we have a Hostile environment inside the system for bacteria: no oxygen, high pressure and saturation of CO2. If you use a small amount of ethanol or oil as a co-solvent the viscosity of the extract is decreased and the deposit of solid parts in the system reduced dramatically. The condition will change immediately when you stop the system and open the lid of the extractor. Ambient air goes inside the extractor/circuit along with any bacteria in the air. The cleanliness of the ambient air is therefore an important factor.
So it is important to reduce the time that the extractor is open, and more time the flow CO2 is arrested, than there are more probabilities of precipitation of solid parts in the piping with negative.