Before revision: The apple cider is then inoculated with either pure acetic acid bacteria or a proportion of 'mother vinegar', resulting in a secondary acetic fermentation which then converts the ethanol in the cider to acetic acid, yielding apple cider vinegar.
After revision: The apple cider is then inoculated with either a pure culture of acetic acid bacteria or a proportion of 'mother vinegar', resulting in a secondary acetic fermentation which then converts the ethanol in the cider to acetic acid, yielding apple cider vinegar.