A few years back, I figured that half-bottles of wine would come on strong. Not the case, despite my reasoning: About half of U.S. adults are single and (one would hope) unlikely to polish off an entire 750-ml bottle in an evening. And in "mixed marriages" — he likes red wine, she prefers white — the same result unfolds if they go the "to each his/her own wine" route on a given night.
Almost inevitably and no matter what measures are taken, the rest of the bottle is not nearly as fresh and tasty whether it's a day later or three. And so wine has been wasted, an egregious sin for many of us. (Oddly, I have had many syrahs that actually were better on the second night, the proverbial exception that proves the rule.)
As soon as a cork is popped or a cap is unscrewed, oxygen can start degrading a wine. Admittedly, some young, tightly wound wines can "open up" with decanting and aerating. Otherwise, the effects tend to be negative. That's why old wines generally should not be decanted, because they already are seeing more life-sucking air than they have in decades.
Restaurateurs have known about this effect for decades, which is why they often charge the same amount for a glass that they paid for the entire bottle; the rest eventually might have to be tossed. Anything served even a day later is likely to be inferior. When ordering by the glass, I always add "if the bottle was opened today," and opt for another wine if it wasn't.
The exception is if the establishment has a wine-preservation system. These glass-encased setups, pioneered locally at Broder's Pasta Bar and at Terzo, use argon and/or nitrogen gas systems to replace the oxygen in the bottle and can keep wines fresh for two to four weeks. They also keep the bottles at a consistent optimum temperature, i.e., cooler than room temp. Other restaurants — including In Bloom, Gianni's, Ngon, the Cooper and Red Rabbit — have added these machines.
Alas, these machines are too spendy to have at home, but we do have some options:
• Buy stoppers, the rubber ones for regular wines and the specialized ones for bubbles (which have the added benefit of making a cool "let's drink" sound when removed). The "Wine Saver" devices made by Vacu Vin work well, too. I haven't had much success with the sprays that some companies make.
• Local wine expert Paul Daggett has always said that sparkling wines don't lose their fizz or freshness in the refrigerator, even without a topper. His explanation was too technical for someone like me, but I've tried it and it has worked.