Because the are swollen from being in the wine bottle, wine bottle corks can be hard to get back into the bottle after they have been taken out . When corks are first put into the wine bottles, they are malleable so they are easy to fit into the bottle. Once they are in the bottle, the wine keeps the corks moist so the cork stays expanded. If you cannot get the cork back into the wine bottle properly, the wine will become stale much quicker. You can, however, put the cork back into your bottle of wine using home techniques.
Fill a pan halfway with water and bring it to a boil. The boiling water will allow you to steam the corks to soften them.
Remove the pan from the heat once the water has come to a boil and put the cork or corks into the pan.
Put the lid onto the pan and allow the cork or corks to steam for 1 to 3 minutes, depending on the type of cork or corks. The corks are done when you can squeeze them lightly between your fingers. Do not steam the corks for too long because they will start to fall apart later; they will also be too spongy and difficult to get into the wine bottle.
Allow the wine bottles to stand upright for one to two days after you have put the cork back in. This will allow the cork time to swell back to its size. Once the cork has swollen back to its size, lay the bottle on its side so that the wine can keep the cork moist.