Apple cider vinegar bacteria metabolize sugars and oxidize alcohols (ethanol) present in apple cider, and produce acetic acid which, in its diluted form, is called vinegar. Bacteria in the commercial product eventually die as holes in their cellular walls show. In addition, the vinegar also contans substances (partly pectin) which were part of the haze in the cider. This image may explain why older vinegar with most bacteria dead may not be used to inoculate fresh apple cider and produce good quality vinegar. SEM image width: 8.5 micrometers. Magnification: 11,765x if the image is printed 10 cm wide.