A closure system for a bottle designed for commercial bottling of a beverage or liquid food, preferably a wine bottle, comprising: a stopper (1, 10, 100, 200, 300) comprising a stopper part for introduction into a mouth of the bottle, and a head part for remaining outside the mouth of the bottle, the head part having a diameter that is larger than that of the stopper part; and a sealing element for sealing the stopper (1, 10, 100, 200, 300) comprising a first part for sealing the stopper part of the stopper (1, 10, 100, 200, 300) against an inner wall of the mouth of the bottle in a sealed position; wherein an inner side of the first part of the sealing element is configured to be pressed by a first portion of the stopper part of the stopper (1, 10, 100, 200, 300) against an inner wall of the mouth of the bottle; wherein the inner side of the first part of the sealing element comprises an interlocking mechanism that is adapted to engage with the stopper part of the stopper (1, 10, 100, 200, 300) wherein the stopper part comprises a means for pressing the sealing element for sealing the stopper (1, 10, 100, 200, 300) against an inner wall of the mouth of the bottle, the sealing element being separate from the bottle, the means for pressing the sealing element being thereby configured to bring the sealing element into a sealed position upon introducing the stopper part into the mouth of the bottle along a longitudinal axis of the stopper (1, 10, 100, 200, 300), in which sealed position the stopper (1, 10, 100, 200, 300) is held on the bottle by way of a frictional connection; wherein the stopper part comprises an interlocking mechanism for engaging with the counterpart interlocking mechanism of the sealing element, the interlocking mechanism being configured to permit bringing the sealing element into an unsealed position upon rotating the stopper (1, 10, 100, 200, 300) with respect to the sealing element around the longitudinal axis of the stopper (1, 10, 100, 200, 300) by moving the stopper (1, 10, 100, 200, 300) in the direction out of the mouth of the bottle; and wherein the stopper part has a first portion positioned between the head part and a second portion on the stopper part, the second portion having a reduced diameter compared to the diameter of the first portion, allowing the pressure exerted by the stopper part on the sealing element to become smaller when the sealing element is brought from the sealed position into the unsealed position upon rotating of the stopper. a stopper (1, 10, 100, 200, 300) comprising a stopper part for introduction into a mouth of the bottle, and a head part for remaining outside the mouth of the bottle, the head part having a diameter that is larger than that of the stopper part; and a sealing element for sealing the stopper (1, 10, 100, 200, 300) comprising a first part for sealing the stopper part of the stopper (1, 10, 100, 200, 300) against an inner wall of the mouth of the bottle in a sealed position; wherein an inner side of the first part of the sealing element is configured to be pressed by a first portion of the stopper part of the stopper (1, 10, 100, 200, 300) against an inner wall of the mouth of the bottle; wherein the inner side of the first part of the sealing element comprises an interlocking mechanism that is adapted to engage with the stopper part of the stopper (1, 10, 100, 200, 300) wherein the stopper part comprises a means for pressing the sealing element for sealing the stopper (1, 10, 100, 200, 300) against an inner wall of the mouth of the bottle, the sealing element being separate from the bottle, the means for pressing the sealing element being thereby configured to bring the sealing element into a sealed position upon introducing the stopper part into the mouth of the bottle along a longitudinal axis of the stopper (1, 10, 100, 200, 300), in which sealed position the stopper (1, 10, 100, 200, 300) is held on the bottle by way of a frictional connection; wherein the stopper part comprises an interlocking mechanism for engaging with the counterpart interlocking mechanism of the sealing element, the interlocking mechanism being configured to permit bringing the sealing element into an unsealed position upon rotating the stopper (1, 10, 100, 200, 300) with respect to the sealing element around the longitudinal axis of the stopper (1, 10, 100, 200, 300) by moving the stopper (1, 10, 100, 200, 300) in the direction out of the mouth of the bottle; and wherein the stopper part has a first portion positioned between the head part and a second portion on the stopper part, the second portion having a reduced diameter compared to the diameter of the first portion, allowing the pressure exerted by the stopper part on the sealing element to become smaller when the sealing element is brought from the sealed position into the unsealed position upon rotating of the stopper.