The racks are used to store the champagne so that the sediment from the sugar and yeast is eased to the neck of the bottle for removal. The sedimentation process takes around 9 weeks with the bottles turned 1/4 of a turn every day. The bottles have a plastic plug inserted to them at time of filling and then a steel cap to seal the pressure of 9 bar in them. When the sediment has settled in the plastic cap the end of the bottle is frozen and then the cap and plug is expelled under pressure. The bottle is then refilled and corked, labelled and ready for sale. The champagne expelled with the plug is kept and used to make champagne vinegar.