Wine + Sustainability with Elizabeth: Volume 5

“We don’t want to let it go to waste, do we?”

Have you ever found yourself uttering those words when deciding to open up a bottle of wine, or when contemplating if you should finish a bottle a wine? The notion of not wasting wine shouldn’t be limited to either of these two scenarios, if we are being mindful of other sustainable choices we can make to reduce waste.

Here at Bin 604, and since at least 2007, we have implemented a procedure that allows us to save that second glass, third glass, and last drop of wine in a 750ml-bottle, days after it has been opened! We have been doing this with the help of a little tool called the Wine Saver.

The Wine Saver is a vacuum pump, which extracts the air from an opened bottle and reseals it with a reusable rubber stopper. A “click” sound tells you when you have reached the optimum vacuum level. The vacuum slows down the oxidation process which makes it possible to enjoy your wine again on a later date.

So that it’s… just pump my open bottle and Voila! I can save that wine for another rainy day, perhaps a month from now? Well, not quite. There are a few other factors that we need to consider, such as:

It’s pumped, now where do I put it?

The best place to store your newly pumped bottle of wine is in the refrigerator. Red or white, it doesn’t matter. Keeping that bottle cold will continue to slow the oxidation process. (If it is a red wine, remove the bottle from the refrigerator about 30 minutes before you want to drink it, to allow it to come back down to room temperature.)

How much wine is left in the bottle?

Needless to say, a ¾ full bottle of wine will keep a bit longer than a bottle with just an ounce or two left.

Is it red, white, sparkling or fortified?

This method is not for sparkling wine. Pumping a sparkling wine, will eliminate any remaining carbon dioxide, killing the bubbles, and leaving you with a wine that is flat.

Is it light, medium or full-bodied?

Thinking in tandem with how much wine is left in the bottle, a light-bodied white wine isn’t going to have the same shelf life as your full-bodied red wine. There are no definitive rules here, as there will always be wines who will break them, but in general you can expect 1-2 days with your light bodied whites and up to 5-7 days with your full bodied reds, with everything else stretching out in between.

How long can I keep and will it taste the same as when I first opened it?

Also working in tandem with the previous point, how long your bottle will last is variable. It is never the same for each bottle of wine. Every bottle of wine evolves differently in the presence of oxygen over time (Scroll down for more on Oxygen and Wine). When we think about wine, what is celebrated is the fact that there are thousands and thousands grape varietals and blends to choose from, and we expect them all to have a distinct smell, look, and taste – before we open it, and after. And while we may not realize it, we are expecting the chemistry* in each of these bottles to be different too.

 *“Wine is a surprisingly complex chemical mixture. It is 97% water and ethanol, but each bottle also contains thousands, if not tens of thousands, of different molecules, ranging from acids and sugars to phenolic compounds and vanishingly low concentration aroma compounds.”

More on Oxygen and Wine

So it essentially boils down to 2 processes; first, flavor compounds reacting with oxygen in the air, and secondly, flavor compounds coming out of solution.

1) Air is essentially 78% nitrogen (N2), 21% oxygen (O2) and 1% other stuff (mostly argon, but also water vapor, and CO2). To simplify you can say 21% O2 and 79% N2 because nitrogen and argon are both very non-reactive. Oxygen is more reactive because it has higher electronegativity (its ability to attract electrons). The arrows on the table show the trends for electronegativity and fluorine is the only atom that is higher.

The ability of oxygen to attract electrons is what causes the oxidation of flavor compounds. Contrary to the term, oxidation doesn’t actually have anything to do with oxygen, it is just the loss of electrons (and reduction is the gain of electrons).

Flavor compounds can either react with oxygen in the air directly (probably a very small amount due to the high amount of energy required for the reaction to happen, which would require much higher temperatures.), or be converted through biological processes by yeast or bacteria. If yeast have oxygen available, different biological pathways are available which allows them to use byproducts of fermentation as energy sources. Some of these byproducts are flavor compounds. Also, yeast in the presence of oxygen will convert ethanol to acetaldehyde (using the enzyme ethanol dehydrogenase), which can produce a green applesour or metallic character. Acetic acid can also be produced by yeast and/or bacteria, which produces vinegar like qualities.

2) A lot of flavor compounds are volatile, which means they are likely to escape from the liquid to vapor phase. By sealing the top of the bottle these volatile compounds are not able to escape into the atmosphere, and at a certain point enough of the dissolved compounds will move to the vapor phase so that the vapor and liquid will be at equilibrium and no more will move to the vapor phase. Pumping the bottle will decrease the pressure slightly, which does shift the vapor-liquid equilibrium more towards the vapor phase, but it is a very small difference, and removing the oxygen from the bottle helps prevent undesired reactions.