A system, device, and method for mixing liquids involves pumping a first liquid into a first pump chamber of a pumping apparatus through a channel of the pumping apparatus and pumping a second liquid from a second pump chamber of the pumping apparatus into either the channel or the first pump chamber, preferably while the first liquid is being pumped into the first pump chamber, so that the two liquids are mixed within the pumping apparatus. The second liquid is preferably pumped in a pulsatile mode in which small quantities of the second liquid are pumped at intervals. The quantity and/or the interval can be dynamically adjusted to result in a predetermined concentration of the two liquids. The contents of the first pump chamber are pumped to a receptacle.