A method for preparing beer or cider concentrate including alcohol and volatile components of beer or cider flavor, and beer or cider prepared therefrom. The method includes a two step concentration method in which the first step involves a high efficiency nanofiltration that results in a highly concentrated retentate and an aqueous permeate fraction comprising alcohol and volatile flavor components. The second step involves removing water from said permeate fraction to obtain a highly concentrated alcohol solution also having volatile flavor components. The highly concentrated alcohol solution is then combined with the retentate from the first step into a final high alcohol and flavor beer or cider concentrate.

Concentration control in filtration systems and associated methods are generally described. Streams originating from upstream filters and having similar concentrations of a target minor component and/or similar osmotic pressures can be mixed and subsequently filtered within additional filters. Certain embodiments comprise recycling an output stream produced by a filter to a filter feed stream, wherein the output stream and the filter feed stream have similar concentrations of a target minor component and/or similar osmotic pressures. Such strategic mixing and/or recycling can reduce the amount of energy and/or the amount of filtration medium surface area required to achieve a desired concentration of the target minor component in a final product stream.