What stops wine coming out of a bottle?

Here's a breakdown:

* Traditional Corks: These are made from the bark of cork oak trees. They are porous, allowing small amounts of oxygen to pass through, which helps the wine age. The cork itself is strong enough to withstand the internal pressure of the bottle, keeping the wine sealed inside.

* Synthetic Corks: These are made from plastic or other materials. They offer a more consistent seal than natural corks and are often more affordable.

* Screw Caps: These are becoming increasingly popular, especially for younger wines. They are airtight and easy to open and close, making them a practical choice.

In addition to the stopper, internal pressure plays a role. Wine bottles are typically sealed under slight pressure, further helping to keep the wine in the bottle.

Here are some other factors:

* Gravity: When the bottle is upright, gravity helps to keep the wine in place.

* Surface Tension: The surface tension of the wine also contributes to its ability to stay in the bottle.

Let me know if you have any other wine-related questions!