Generally, an extraction system useful in separating an extract from a matrix using one or more extractants. Specifically, an extractor including one or more of: an extraction vessel having an extractor vessel internal surface which defines an extraction chamber which communicates between open extraction vessel first and second ends, a first piston configured to sealably engage the extractor vessel internal surface of the extraction vessel first end or a second piston adapted to sealably engage the extractor vessel internal surface of the extraction vessel second end.