I did not think that the bottles remain in fact so well preserved. I have specially made a comparison, opened two white wine bottles and both half drunk. The one I pumped empty, the other closed again with the cork. The difference already after 12 hours was striking. Of course, the wine is not vacuumized-pumped by the time faders and blunt, but no comparison to. I have the money for the wine pump after 2 weeks due to non-weggeschüttetem wine loose out again. Clear buy!