A brewing system and method are shown for brewing a beverage, such as coffee or tea. The system includes an inline sensor or sensor array that intercepts the dispensing stream and measures the time dependent properties of the brewed liquid at a particular location as the liquid is dispensed. In a particular embodiment, the total dissolved solids is measured to produce a coffee signature, which is sent to a controller that uses the time-dependent data to perform one or more of the following: evaluate the quality of the brewed liquid, control the brewing process for subsequent brewing cycles; identify the blend or brand of brewed product; and/or determine when maintenance is needed or advisable for the brewing system.