Wine Saver – Round One: Competing with the Screwcap
Of the diverse methods available intended to preserve an unfinished bottle of wine after opening, the vacuum pump is probably the most popular, is certainly one of the most practical and is also one of the cheaper alternatives. But does it work?
Well I can give you a one-word answer to that: no.
Allow me to qualify that “no”: my tests at home, with several different good-quality wines with screwcap closures, indicated in every case that freshness and fruit was better-maintained simply by screwing the cap back onto the respective wine bottle than by using the vacuum pump and stopper. This does not mean that the development of the wine over the test period was preferable – in fact, among my test subjects, it was 50/50 which wine was preferred.
Sorry if that pisses you off, sorry if you disagree. I’ll explain how I arrived at my conclusions shortly.
What Do They Do?
The stated purpose of a vacuum pump is to remove air from the bottle. The goal of this rather simple operation is twofold:
- to create a good seal to prevent air from entering the bottle and, more importantly,
- to reduce the oxygen remaining in the bottle, thereby slowing down the rate of oxidation of the wine
It sounds good, and it makes sense that removing air from the bottle should slow down the oxidation of the wine. The system itself is quite simple: a rubber stopper with an internal valve is placed in the neck of the open bottle, a pump designed to work with that stopper is used to draw air out of the bottle until an “ideal” level is reached – or simply no more air can be removed, which is not to say that there is no more air inside the bottle. In the case of VacuVin, the latest pumps will make a clicking sound once the “ideal” state is reached.
So far, so good. If the seal is effective, it should be obvious when the stopper is removed. The valve on the stoppers can be manually released, allowing pressure inside and outside the bottle to equalise. When comparing with a bottle closed only with a screwcap after opening, but at a similar fill level, opened at the same time and stored in the same conditions, it should be a no-brainer that the wine with less air in the bottle oxidises less quickly.
Should be. My tests – for all bottles tested – show otherwise.
Before going on, I should mention that my stoppers worked just fine at creating a seal; the pump worked just fine at removing air. Everything worked just as they were supposed to.
What I Did
The wines I chose for testing shared the following features:
- monovarietal – Garnacha for the reds, Weissburgunder (Pinot Blanc) for the whites
- sealed with screwcap
- reductive vinification (exposure to oxygen during vinification or aging kept to a minimum)
- steel tank fermentation and ageing, little contact with the lees
- large volumes of production
I chose red wines and white wines of good quality, with all test bottles coming from the same batch. I wanted screwcaps and reductive vinification to minimise bottle variation and the influence of oxygen. This was to ensure that the wine from all the test bottles tasted the same at the start. Reductive vinification was also important to permit the gradual oxidation of the wines after opening to be as clear as possible at subsequent tastings. I wanted the vinification to have been done in steel tanks (instead of wood barrels) so that there would be no wood influence on the wines, and because it is important for reductive vinification.
- four standard (750 mL) bottles of each wine were opened simultaneously and tasted for consistency
- the bottles were divided into two pairs (Pair 1 and Pair 2), with each pair consisting of one bottle to be resealed with the vacuum pump system (Bottle A) and one bottle to be resealed with its screwcap (Bottle B)
- the bottles were tested several times over the subsequent 96 hours
- after each tasting the bottles were resealed appropriately and placed in the refrigerator
All tastings were conducted blind.
I chose to test two pairs of bottles to allow a different fill-level as the start point for the tests. One large glass (187 mL) of wine was removed from each bottle at the time of each tasting after the first, each bottle contains four large glasses of wine in total.
This pair had one glass of wine removed at the time of opening, so it was ¾ full when it was first resealed. Subsequent tastings were at 48 hours, 72 hours and, finally, at 96 hours.
This pair had two glasses of wine removed at the time of opening, so the bottle was ½ full when it was first resealed. Subsequent tastings were at 48 hours and 96 hours.
Results of the Tastings
The differences between the two bottles were already clear at the first test after 48 hours, and became more pronounced with each subsequent tasting. Bottle A became softer and rounder earlier than bottle B – it also lost freshness sooner. In the whites the fruit flavours were disappearing, in the reds they had moved considerably into “prune” territory. whether you enjoy these effects on a wine or not, they are all indicators of oxidation.
Conclusion: oxidation was simply more advanced in the bottles sealed with the vacuum pump system.
So, on the basis of what the stated purpose of the vacuum pump is, which, as I said, is to slow the rate of oxidation, I must say that it did a poorer job than simply screwing the cap back onto the bottle.
As I mentioned above, half of the people I tasted the wines with preferred the more rounded, softer wine. That’s fine, too. Personally, I preferred the fresher ones; I preferred Bottle B in all cases and at every tasting.
This test was conducted on screwcap wines that were made reductively. The results with wine sealed with cork and made in a less reductive fashion could be different. At the very least, the differences might be less noticeable. I’ll likely try that sometime soon.
If you are planning on drinking your wine over the space of a few days, don’t even worry about pumping out air or finding another alternative for “saving” your wine. Put in a good stopper if the wine isn’t screwcap or just put the screwcap back on. It’ll be fine. If you need to save your opened bottle of wine for a couple weeks…. Well, maybe you should invite someone to drink it with you instead.