Wine and olive oil have a common enemy – oxygen. It oxidizes their flavors and aromas so that they loose their complexity, become boring and dull, and may even acquire defects. What is the cheapest and the most effective way to protect your wine and olive oil at home? Use a aerosol spray can filled with argon, a noble and inert gas that forms a protective blanket on the liquid surface.
In wine oxygen works faster, partly because there are also acetic bacteria that will use it to turn alcohol into acetic acid. Wine that remained in a closed half finished bottle for just 24h will already be altered and in few days it may become even undrinkable so that you can either pour it down the drain or try to make your own vinegar. What to do if you would like to take five bottles of wine and open them at once (of course, not to get drunk, but just to taste different flavors and aromas one after another, or to change wine with each course)? Or, you own a wine bar or a restaurant that serves wine by glass and would like to keep the wine quality unaltered?
There are several methods which can slow down or completely stop wine spoilage. The simplest one is to put the bottles in the fridge. In that way, the acetic bacteria reproduce more slowly than on ambient temperature. From my experience, this method is applicable only for one day and the results are not very good because you do not prevent aroma and flavor oxidation. There are observations that intense reds will loose the flavor intensity and acidity when kept only for a day in the fridge.
The second method is to use a wine saver vacuum pump. According to this post, the pump is worthless since the sucking pressure it generates is too low to remove much air from the bottle. Nevertheless I should give it a try; maybe it is effective at least for 3-4 days that is enough time to consume the entire bottle? The third method is to replace air in the bottle with some non-oxidizing gas.
In case of olive oil only the third method is used. In fact, before bottling the oil is usually stored in large stainless steel tanks in which large surface of oil comes in contact with the air. Oil oxidizes more slowly than wine – a month or two are needed for any perceptible change in aromas and flavors. The worst thing it may happen is that the oil in six months can even get rancid and therefore loose its precious extravirgin status.
Which gas is used in the third method, knows also under the name tank blanketing? The most common is nitrogen since it is cheap and easily available. The problem with nitrogen is that it has density of 1.251 g/L which is comparable to the density of air (1.2 g/L), so the pressure of nitrogen inside the tank needs to be kept constant. Therefore, you need to buy an expensive bottle and a pressure controler connected to your container (see the picture above).
Argon, on the other hand, is heavier (1.784 g/L) than air which makes its usage much easier. You need to buy it packed in aerosol spray can can so there’s no need to bother with valves, tubing and pressure controllers. It is enough to gently spray it for 2-3 seconds in the bottle or stainless tank and heavy, inert argon molecules will sink down and form a protective blanket on the liquid surface (surface blanketing effect). The oxygen will no longer be in contact with the liquid.
Unfortunately, it is hard to find argon in aerosol spray on the market. Here are some web shops where I found what we need:
Argon (99.995%) 4 L from Sigma-Aldrich 75.30 €
Gives an application to about 120 bottles of 0.75 L. It is ultra high purity argon sold for laboratory use. It is also completely suitable for alimentary use, but its price way too high. We need to find something cheaper.
Private Preserve – Wine Preserver on www.amazon.co.uk 12 £
Again, 120 bottles of 0.75 L can be preserved. It is a mixture of nitrogen, carbon dioxide and argon that are all gases suitable for oxygen blocking. The gas mixture density, a factor important for efficient surface blanketing, is not specified. I presume the manufacturer have put inside more argon and carbon dioxide (heavy gases) than nitrogen (light gas) to keep the average density at least 30% higher than the air density.
Very similar to Private preserve. It is not pure argon but a mixture of oxygen blocking gases (probably also nitrogen, carbon dioxide and argon).
Ultra Wine Saver $19.95$
99.99% Argon. Very nice and ergonomical design. One argon cartridge ($2.75) gives an application to about 18 bottles of wine.
Bloxygen Gas 9.95$
120 bottles of 0.75 L can be preserved. I checked the composition and they claim it is 100% Argon. Disclaimer: This product is sold for preserving unused finishing materials. The exact composition should be double checked with the producer to see if the product is suitable for alimentary use.
Hope I did not bother you too much with such a long and technical article. I think it will be useful to many wine and olive oil enthusiast in Istria who have never heard of this cheap and useful technology.