by Jeff Miller
It’s a problem that just keeps cropping up—you’ve finished half the bottle, which means that you still have a half a bottle left over that, hopefully, you’ll finish in a day or two.
All too often, when you come back to it, it’s no longer drinkable. Usually, oxidation (which, as the word implies, results from exposure to oxygen) is the problem. At any rate, another half a bottle down the sink. Can this be avoided?
Before answering this question, it is worth noting that wines vary greatly in how long they will last once open. Younger, more tannic, reds seem to be able to last much longer than lighter, older, ones. Whites, properly corked and refrigerated, seem to be able to last quite a while. Fortified wines can last for months without undue distress. But a dry red wine, young or old, sooner or later will turn on you.
There are two main types of products on the market that aspire to overcome this problem, both by eliminating the oxygen in the bottle. The first type is an aerosol can that contains inert gas (usually carbon dioxide, nitrogen, argon, or some combination). This employs the same method used in a winery for partially full tanks, where inert gas, normally argon or nitrogen, is used to fill up the headspace in the tank, thus keeping out oxygen. The theory is impeccable. The reality less so. My experience is that no matter how much of the gas you put into the bottle, the results are only so-so. I think that the problem is that you can eliminate most, but not all, the oxygen, and most isn’t good enough. So while this method is better than nothing, it falls far short of optimal.
The second main means of preserving the wine uses some sort of vacuum method. Most common is a rubber stopper with a slit in the top. You then use a plunger type device that sucks out most of the air from the bottle. They do seem to achieve this, since when you pull the stopper out, there’s a rush of air into the bottle filling up that partial vacuum. But you’re not eliminating oxygen from the bottle, just diluting it. And, as with the aerosol can, getting rid of most of the oxygen isn’t the same as getting rid of all the oxygen. These devices are better than nothing, but no panacea.
There’s a third method, and it’s what winemakers use. It is by far the most effective of the three. It’s also very simple. It suffers from the fact that it’s hard to make any money off of it, so no one has an incentive to push it.
This is what you do: take that half-filled bottle, and pour it into a smaller bottle. You can use a funnel at first, but you’ll quickly develop the ability to pour from the original bottle directly into the smaller one. The important thing is that you fill it all the way to the very top. Don’t use a cork—use a screw-capped bottle instead, so that you eliminate all air. I use what are called sample bottles, which can be obtained in various sizes, but a 375 ml size (half a normal 750 ml bottle) is perfect for that half empty bottle. It’s closed with a plastic screwcap. If you can get your hands on a few of these, great. (If you can get your hands on the 500ml and 187ml sizes as well, you’ll have an assortment which will allow you the flexibility to preserve differing amounts of leftover wine.) Any screw-cap bottle will work pretty well, however. An clean, empty water or soda bottle will do. The important thing is that fill it all the way to the top so you have zero air left in the bottle.
This method will not be the equivalent of an unopened bottle of wine. For one thing, oxygen got into the wine when you first opened it, which has now become absorbed into the wine itself, and can’t be removed. Normally, there’s enough sulfur dioxide in the wine (all wine has it, pretty much) to bind to this amount of oxygen, and keep it from destroying the wine, at least for a few days. Nor is this type of screw cap going to keep oxygen out indefinitely (the oxygen seal for this type of screwcap isn’t intended for long-term storage). The point isn’t to put that half finished bottle down for a few years, just to buy a couple of days till you can finish it off. And for that purpose, except for the most fragile of wines, this method works.
There’s always the problem that you never have exactly half a bottle left. Always a little more or a little less. If you have a little too much, it is far better to pour out some excess wine and have an air-free bottle for what’s left, than it is to store more wine in a larger, partially air-filled, bottle. Less good wine is far better than more bad wine. If the thought of discarding some amount of wine is unacceptable, then you need to get even smaller sizes of bottles to handle the excess.
If the problem is that you don’t have enough wine to fill up the half bottle, there’s an easy solution. Get some marbles, wash them off, and put as many as necessary into the bottle to top it off. Since wine kills off any microbes that can harm you, the marbles don’t need to be antiseptic clean. Just as long as there’s no dirt or grime on them, you’ll be fine. (Actually, a little dirt or grime probably wouldn’t be that big a problem either.)
If you have way too little to fill half a bottle, then you just need to get smaller bottles. The one-serving size screwcap wine (or spirits) bottle will come in handy for this situation.
Since wines vary, there’s no absolute rule to how long these wines will last before becoming unacceptable. For most wines, however, you can count on getting at least a few days. For many wines, a week or more isn’t out of the question. A very sturdy wine can go even longer.
Finally, there’s the problem of the bottle you didn’t finish because it wasn’t that good. There’s not a whole lot of point to preserving it for another day, because that day probably will never come. If you’re like me, that bottle hangs around long enough to go off no matter how well it’s stored, at which point I discard it without guilt. The better choice for that wine would have been “down the sink” at once. There’s too much good wine out there to waste your time with second-rate plonk.