Convenience stores are provided a beverage water processor for coffee and beverages. The "ideal" total dissolved solids (TDS) of perhaps 110 parts per million is achieved without a blendback process. The R/O water is remineralized with a flow through calcite bath. A potassium chloride source is used to inject the exact amount of potassium chloride needed to reach the ideal TDS on the fly before the water reaches the storage reservoir. Alarms trigger a bypass loop to keep the store in business during shutdown. All output water passes through a UV sterilizer.