The Gemara in Masechet Shabbat (146) establishes the prohibition against creating a Keli (functional utensil) on Shabbat. In light of this prohibition, the Halachic authorities address the question of whether it is permissible on Shabbat to open a new bottle, such as a soda bottle or bottle of wine. The bottle itself already has the status of a Keli before one removes the cap, but the cap perhaps becomes a Keli as a result of its removal. Even though the cap already serves as a utensil in that it covers the bottle, breaking the ring that attaches the cap to the bottle enables one to use this cap to cover a different bottle, and it would thus seem that removing the cap transgresses the prohibition of creating a Keli on Shabbat.
Chacham Ovadia Yosef, however, rules that it is permissible to open a new bottle on Shabbat, because people generally do not use the cap from one bottle to cover a different bottle. Therefore, since the cap already functions as a Keli with respect to the original bottle, one does not create a Keli by removing it. Of course, it would be forbidden to remove the cap for the purpose of using it to cover a different bottle; but assuming one opens the bottle with the intention of using the cap only for that bottle, it is permissible. This is the position as well of Rabbi Moshe Halevi, in his work "Menuchat Ahava."
Many other authorities, however, rule stringently on this issue, claiming that removing a bottle cap transforms it into a Keli even with respect to the original bottle. Rabbi Moshe Halevi therefore recommends opening one's wine bottles before Shabbat. As opposed to carbonated drinks, which would lose their carbonation if the bottle is opened before Shabbat, wine would not be adversely affected if one opens the bottle before Shabbat, and one should therefore endeavor to do so in deference to the authorities who forbid opening bottles on Shabbat. With regard to carbonated drinks, however, one may certainly rely on the lenient view and open them on Shabbat.
Summary: One may open new bottles on Shabbat, provided that he does not intend to use the cap to cover a different bottle, though it is preferable to open one's wine bottles before Shabbat, as this would not diminish from the taste and quality of the wine. Bottles of carbonated drinks, however, may be opened on Shabbat and one need not be stringent in this regard.
