In the world of wine, air is the enemy. Or more specifically, oxygen is the enemy. Let me step back a second. Air serves a very important purpose when you're drinking wine. Most importantly, it "opens up" a wine and helps to bring out its character. When you slosh wine from a bottle into a glass, a lot of air gets mixed in. This causes those aromatic compounds to fill the glass and makes the experience of drinking a good wine all that much better. There are decanters and aerating gadgets to speed up this process, too, if swirling's not your thing. But once air gets to the wine, the cat is out of the bag. While it will taste fantastic for a few hours, it will then slowly lose its fruitiness, its aroma, its body, and just about everything else. Eventually the wine will oxidize due to exposure to O 2 in the air, which starts a chain reaction in the wine, forming hydrogen peroxide, then acetaldehyde, neither of which you want to be drinking a lot of. Once a wine is uncorked (or once the cork starts to fail), this process begins in earnest. So what do you do if you want to drink a single glass of wine but not throw away the other four-fifths of the bottle? You turn to a wine preservation system. There are three main tactics to arrest oxidation, and gadgetry is available for each. They are: 1. Suck the air—including the oxygen—out of the bottle, leaving a vacuum.

2. Replace the bad air with good air; some inert gas that won't interact with wine.

3. Form a physical barrier between the wine and the air. (You can also do this by pouring the remainder of a larger bottle of wine into a half-bottle and resealing it such that no air is left between the wine and the cork.) Which one works best? I've been writing about wine for more than a decade and have tried all three of the above strategies many times over. I have developed opinions about each method, but until now I'd never done any formal, controlled testing between multiple devices. For this report, I used my informal test results as a guideline but am largely relying on this fresh, formal analysis. How We Tested I purchased seven bottles of the same wine (a California Cabernet Sauvignon). Five were opened and tasted to ensure they weren't tainted in some way, and the same amount of wine was poured or extracted from each bottle. The five bottles were each sealed for two days using one of five different preservation systems. After 48 hours, the wines were tasted blind (i.e., with no advance knowledge of which glass was which) and were rated based on how close they tasted to a freshly opened bottle. The wines were then resealed for another five days. On day seven, the blind testing was repeated against another fresh bottle of wine. My wife, who is a wine industry professional and seasoned taster, also tasted all the wines with me. Our marks were very similar across the board. I'm not the first person to attempt this test, so remember that every vendor can and will point to its own results that show that without a doubt that its product is the best at preserving wine. They might actually be right: Different wines keep better under different conditions. A big Chardonnay may keep for days under a vacuum seal in the refrigerator, but a delicate old Burgundy could fade in hours unless it's treated with the dignity it deserves. That said, the big picture shakes out like this.

Vacu Vin Wine Saver This is the preservation system just about everyone starts on. It's cheap, brainlessly simple to use, and for overnight preservation, it usually works well. Just pop a special rubber stopper into the bottle's mouth, then press the hand pump to the top. Pull back a few times and air gets sucked out of the bottle, creating a (somewhat weak) vacuum. A clicking noise alerts you when the pump can't extract any more air. Vacu Vin Wine Saver Mechanism: Hand-pumped vacuum

$10 (extra stoppers cost $2 each)

vacuvin.com In theory it's a perfect solution: If air is the enemy, then no air is the answer. Getting the air out of the bottle should theoretically protect the wine indefinitely. The trouble is the part where you create a vacuum by hand. How much air can you realistically pull out of a wine bottle with a $10 piece of plastic? Some have actually measured the strength of the vacuum created and calculated that it's only about 70 percent complete, and that's on a fresh pull. That leaves plenty of air in the bottle, plus, over time, there's fear that a Vacu Vin seal leaks, letting in even more air every day. Furthermore, some have speculated that the process of creating the vacuum sucks out the volatile esters from the headspace in the bottle, essentially removing flavor compounds along with oxidizing elements. In reality, that's a whole lot of doomsaying over a stocking stuffer, and for short-term wine keeping, Vacu Vin works better than detractors claim. In fact, in my two-day test, the Vacu Vin wine earned my highest score. I couldn't tell it apart from a fresh bottle. But things went south—way south—after a week. At the seven-day mark, the Vacu Vin wine had become extremely musty and was completely undrinkable, lending credence to some of the theories about its long-term effectiveness. For short-term storage, Vacu Vin is foolproof and works fine, but if you need to keep an open bottle for more than 48 hours, look elsewhere. WIRED The most affordable wine preservation system this side of sticking a cork in the bottle. Easy to apply to multiple bottles at once. Fast and idiot-proof. TIRED Completely ineffective after a couple of days. Easy to accidentally bump seal and break vacuum. Sealed bottles can't reliably be stored on their side. Rating: 7 out of 10

Private Preserve It takes quite a leap of faith to put your trust in Private Preserve. This can of inert gasses—nitrogen, carbon dioxide, and argon—feels empty when it's full. To use it, first you read the instructions. (There's enough text emblazoned on the surface of the can to make Dr. Bronner jealous.) Then, following the steps outlined, just remove one of the WD-40 style mini-straws, connect it to the nozzle, and insert it into a partially-consumed bottle of wine. A specific sequence of long and short compressions (described on the canister) sprays a blanket of this invisible gas atop the wine, then you quickly seal it shut, ostensibly sealing in what's inside. Private Preserve Mechanism: Inert gas spray

$9 (120 uses)

privatepreserve.com Did you do it right? Well, there's no way of knowing until the next time you pour a glass from the bottle. That said, if you do use Private Preserve correctly, it really does seem to do the trick. Blind tastes of wines preserved for two days and seven days with the product earned some of the highest marks in my comparison. I couldn't tell much of a difference between a fresh bottle of wine and one preserved with Private Preserve for a week. And after just two days, I actually thought the Private Preserve bottle tasted better than a freshly opened one. The bottom line is that air may be an invisible killer, but the stuff inside Private Preserve is clearly even stronger. At a price that equates to less than a dime per use, this is a low-risk way to keep your wines intact. WIRED Perhaps the best overall at preserving wine; the company says it's had wines opened for over four years under Private Preserve no ill effects. Cheap. Usable on multiple bottles simultaneously (and other non-wine products, too). TIRED Bottles must be stored upright. Cork jammed back into the top of a bottle doesn't scream elegance. Instructions vary on website versus bottle. Practice before trusting your Petrus to it. Rating: 9 out of 10

Air Cork Not the most elegant of wine preservation systems, the Air Cork at first looks a bit like something you'd find at Spencer Gifts. The idea behind it is simple: You insert a deflated latex balloon into the neck of the bottle. It's connected via a hose to a hand pump, which you squeeze to inflate the balloon until it forms a seal against the sides of the bottle. Getting the height right so there's minimal air trapped between the balloon and the surface of the wine is tricky, but making tweaks is easy enough. A valve releases the air out of the balloon so you can remove the mechanism when you want another drink. Air Cork Mechanism: Inflatable rubber barrier

$25 (extra balloons $5 each)

aircork.com The overall appearance of the Air Cork, whether inflated or not, is a little disconcerting, but the impact it had on my test bottle was worse. In blind testing, the wine was decidedly unpleasant by day two, with a distinct chemical taste to it. Things were only marginally worse at day seven, though at least the chemical notes had faded considerably, leaving behind a merely dull, lifeless wine with no fruit left in it — worse than a wine that had been sitting with just a cork in it at that point. My theory is that the wine's contact with the rubber in the balloon affected it even more than the air, although the company explicitly claims it will not. That said, I had better luck with Air Cork on other test bottles (not tasted blind), so I won't write it off completely. But there are better options available. WIRED Seals bottle without extra height (making it more likely to fit on a refrigerator shelf). TIRED Relatively ineffective, even for short-term use; even the company says a seal is good for just three days before re-pumping is required. Looks juvenile. Requires cleaning. Unclear what long-term impact of rubber on the wine might be. Rating: 4 out of 10

Savino The Kickstarter-launched Savino (save+vino) is the only product in this roundup that requires you to take the wine out of the bottle for it to work. On one hand, that's good: The Savino is elegant and sophisticated and lets you pretend your Yellow Tail is Chateau Lafite. On the other hand, that's just more stuff you have to clean before bedtime. The idea is similar to the Air Cork. Pour the wine into the Savino, then drop a hollow plastic disc on top. The disc floats to the top of the wine, and a silicone ring around the edges blocks virtually all of the wine's surface from being exposed to air. Savino Mechanism: Custom decanter with floating plastic barrier

$60

savinowine.com That's the idea, anyway. Results with the Savino were mixed and, in fact, a little baffling. After two days, the wine in my blind taste was at its worst, a funky, musty wine that had begun to taste astringent and was developing some of the same chemical notes as the Air Corked wine. But on day seven, things had settled down. At this point, the wine was tasting fresh and fruity, with none of those off notes. In less formal tests, I've also had inconsistent results. One wine will taste fine after four or five days, another will turn sour after 24 hours. What to make of all of this? Maybe it's best to use Savino as a simple decanter, and drop in the preservation disc topper if you don't happen to finish it off... then hope for the best. WIRED Handsome. Easy to use: Dump in wine, drop in the float. TIRED Inconsistent performance. Lots of stuff to clean (disassembles into five separate pieces). Needs special care to avoid sunlight and jostling the carafe. One wine at a time only. Seems pricey. Rating: 5 out of 10