A brewing method where stronger-than-usual worts go through fermentation, and the concentrated beer that results is watered down to normal strength before packaging. It raises brewery throughput and saves tank space and energy, but the yeast faces greater osmotic and ethanol stress, so fermentation control and flavour management need extra attention. Off-flavours from stressed yeast and incomplete attenuation are the main risks, and brewers manage them through yeast selection, nutrient dosing, and careful dilution-water quality. The technique is standard in large contemporary breweries producing consistent mainstream lagers.