A bioreactor with a system for condensing moisture in a moist gas stream entering or leaving the bioreactor, the system comprising: a condenser container (20;30) capable of holding a fluid, the condenser container being a flexible bag and comprising: an outer wall surface and an inner wall surface, the inner wall surface defining an interior chamber for holding the fluid; a first fitment attached to the outer wall surface of the condenser container, the first fitment forming a first port configured to allow the moist gas stream to flow through the first port and into the interior chamber; a second fitment attached to the outer wall surface of the condenser container, the second fitment forming a second port configured to allow a dried gas to flow from the interior chamber and out of the second port; and a cooling device in contact with at least one portion of the outer wall surface of the condenser container and arranged to cool the at least one portion of the outer wall surface of the condenser container, thereby condensing moisture in the moist gas stream entering or leaving the bioreactor, wherein said cooling device comprises a cold plate and wherein a frame (46,48) forms a sandwich with said condenser container held firmly against said cold plate, characterized in that said condenser container further comprises a third fitment for draining condensate and being configured for recycling the condensate to the bioreactor via tubing attached to the third fitment. a condenser container (20;30) capable of holding a fluid, the condenser container being a flexible bag and comprising: an outer wall surface and an inner wall surface, the inner wall surface defining an interior chamber for holding the fluid; a first fitment attached to the outer wall surface of the condenser container, the first fitment forming a first port configured to allow the moist gas stream to flow through the first port and into the interior chamber; a second fitment attached to the outer wall surface of the condenser container, the second fitment forming a second port configured to allow a dried gas to flow from the interior chamber and out of the second port; and a cooling device in contact with at least one portion of the outer wall surface of the condenser container and arranged to cool the at least one portion of the outer wall surface of the condenser container, thereby condensing moisture in an outer wall surface and an inner wall surface, the inner wall surface defining an interior chamber for holding the fluid; a first fitment attached to the outer wall surface of the condenser container, the first fitment forming a first port configured to allow the moist gas stream to flow through the first port and into the interior chamber; a second fitment attached to the outer wall surface of the condenser container, the second fitment forming a second port configured to allow a dried gas to flow from the interior chamber and out of the second port; and a cooling device in contact with at least one portion of the outer wall surface of the condenser container and arranged to cool the at least one portion of the outer wall surface of the condenser container, thereby condensing moisture in the moist gas stream entering or leaving the bioreactor, wherein said cooling device comprises a cold plate and wherein a frame (46,48) forms a sandwich with said condenser container held firmly against said cold plate, characterized in that said condenser container further comprises a third fitment for draining condensate and being configured for recycling the condensate to the bioreactor via tubing attached to the third fitment.