|gfink (at) hsph.harvard.edu
|ahealy (at) fas.harvard.edu
We found that simply recorking the bottle was quite effective, although the VacuVin pump performed better. Remarkably, the "Private Preserve" system was found to be inferior to simply recorking the bottle (for both wines used in the experiments).
Volumes have been written on the ideal conditions for storing unopened bottles of wine, but a more pragmatic question for most wine-drinkers is that of how to store leftover wine from an unfinished bottle. The easiest method is to simply recork the bottle; however, various more sophisticated methods exist including using a vacuum pump to reduce the amount of air in the bottle, blanketing the wine with inert gas or decanting the leftover wine into a smaller bottle (with little or no room for air).
The Experimental Setup
Three days after sealing the bottles, we removed them from the refrigerator and let them come to the same temperature as the control bottles (50°F for the white wines and 62°F for the red wines).
For the three remaining white wine samples, the results were as one might expect: the newly-opened sample had the freshest and most focused character, with the VacuVin sample coming in a close second. The recorked sample survived remarkably well, although was noticeably less fresh and flavorful than the newly-opened and VacuVin samples, at least in a side-by-side comparison.
For the reds, we noticed differences among the three remaining samples, although they were difficult to classify as the wine
continuned to evolve in the glass. We originally identified the recorked bottle as having the "roundest" flavor and the
freshly-opened sample as being a little "harsh", with the VacuVin sample somewhere in between. Fifteen minutes later (alas,
only after we looked at the identifying labels on the bottoms of the glasses -- so we cannot claim that these tastings were
conducted blind), we found that the freshly-opened sample had "opened up" considerably, and was superior to the VacuVin and
recorked samples (which had now begun to fade and lose their appeal), as one might have expected.
Conclusions and Future Work
The poor performance of the Private Preserve gas is counterintuitive and certainly does not agree with the anecdotal evidence of many wine-writers. We feel that this warrants further study, and in particular, we hope to conduct a similar experiment comparing the Private Preserve gas with a pure-nitrogen system such as the Wine Keeper system (again, using unopened bottles as a control).
Of course, there are many further tests that can be conducted to corroborate and/or complement this experiment. Perhaps the most effective preservation methods depend of the age or style of the wine? How do various preservation systems work at room-temperature? And the list goes on.
We hope to address these and other questions in future experiments of this kind.