An adjustable volume sampling system is disclosed for aseptically retrieving a sample volume of a fluid from an origination container. The system includes a sampling container. A cap is removably attached to the sampling container so as to close off the open top. The cap includes two ports. A first tube is attached to one of the ports. An elongated diptube extends through port into the sampling container and an upper end of the diptube is located inside a portion of the first tube. The diptube can be raised and lowered relative to the sampling container by pinching an stretching the first tube. Syringes are provided for expelling excess material from the sampling container.