sterile bottling or, more correctly, aseptic bottling is the technique of getting wine into a closed bottle without incorporating any micro-organisms (notably yeast and harmful bacteria). Borrowed from the pharmaceutical packaging industry, this technique does the job of pasteurization without the use of heat. Aseptic techniques have become the norm for wine bottling because the use of membrane filters (see filtration) has made the task very simple. Many everyday modern wines have small amounts of residual sugar and therefore require bottling in an aseptic manner, but the degree of care needed depends upon the levels of residual sugar and alcohol.
