How Inert Gas Is Used in Winemaking

Several people have heard about the large number of applications that call for specialty gases. From welding and cutting, to research in laboratories, to the pharmaceutical industry, the variety of uses of compressed gases seem almost limitless. However, less commonly discussed is the utilization of specialty gases in an industry that directly pertains to nearly all people worldwide- the food and beverage industry. As an example, whether you’re a wine aficionado or someone who prefers the occasional glass at dinner, you might not be aware that there are some specialty gases actually are a significant factor in the process of making wine.

If a wine is not protected from both oxygen and microbial spoilage during the aging process, it is likely to go bad. In order to safeguard the wine, it is important to maintain adequate sulfur dioxide levels and keep containers full. Also, the amount of protection is notably increased by purging headspaces with inert gas in order to get rid of the oxygen. In regards to sulfur dioxide, its advantages and details about its utilization in this process can be seen in a lot of winemaking literature. However, while these texts may briefly discuss purging with inert gas, they frequently do not efficiently explain the actual techniques required to perform the application. First, it should be understood that it requires more than merely dispensing some argon into the headspace of your vessel in order to generate a sufficient gas blanket to preserve your wine. The goal of this article is to discuss the techniques required to adequately use inert gas to purge headspaces in order to successfully safeguard your wine. First, we will detail the significance of safeguarding your wine from being exposed to oxygen, and afterwards we will explain the precise gas purging methods required to do so.

The space in a barrel or tank that is not filled by liquid is filled by gas. As is commonly known, the air we breathe is a mix of gases, approximately 20% of which is oxygen. While a consistent supply of oxygen is necessary for humans, it is certainly not beneficial when it comes to the safe storage of most wines. The explanation for this is that a series of chemical changes occur to wine when exposed to oxygen. If wine is exposed to oxygen for an uncontrolled, lengthy period of time, then the resulting changes produce undesireable flaws in the wine such as a diminishing of freshness, browning, sherry-like smells and taste, and acidity production. Wines possessing theseflaws are referred to as oxidized, because they occur as a result of exposure to oxygen. One of the main objectives in correct wine aging is learning the best techniques to decrease the wine’s oxygen exposure in order to avoid oxidation. One easy method to do so is to fill the wine’s storage vessel as full as possible, in order to eliminate headspace. However, this technique may not always be possible.

Unless you are storing your wine in a storage vessel that is guaranteed to resist temperature changes, carboys and tanks should have a small headspace at the top in order to facilitate the contraction and expansion that occur to the liquid when the temperature changes. Because gas iseasier to compress than liquid, it does not significantly increase the pressure in the storage unit if there is some space left at the top. This is the reason that you find a quarter-of-an-inch space below the cork in a new bottle of wine. If there is no headspace and the wine experiences a rise in temperature, it will expand and the subsequent pressure will end in the full force of the liquid being pushed against the lid. In some extreme spikes in temperature, this pressure could even be enough to push the tank lids out completely. If this were to happen, not only have you potentially caused a mess and lost wine, but your wine is now exposed to elements that could cause it to spoil. In an extreme temperature decrease, on the other hand, the lids would be pulled inward as a consequence of the liquid contracting. Thus, if there is a possibility that your wine could be exposed to temperature variations throughout its storage, headspace should be left at the top of vessels.

While we now know we must leave a headspace, we still are left with the problem of leaving room for contraction and expansion while at the same time avoiding the negative effects of oxidative reactions. The solution, however, is found by replacing the headspace air that contains oxygen with an inert gas, such as argon, nitrogen, or carbon dioxide. These gases, unlike oxygen, do not negatively react with wine. In fact, carbon dioxide and argon actually weigh more than air, a property that proves advantageous to winemakers. Purging headspaces with either carbon dioxide or argon, when properly performed, can eliminate oxygen by lifting it up and eliminating it from the storage vessel, similar to how oil can float on the surface of water. The oxygen in the vessel has now been sufficiently displaced by inert gas, and the wine can remain safe from negative reactions during its storage/aging process. The primary factor to effectively preserving the wine in this way is to be aware of the specific techniques required for the proper formation of this protective blanket.

There are 3 steps that are helpful to form a protective inert gas blanket. The first step is protecting purity by avoiding turbulence. When employing carbon dioxide or argon to create [[a successful|an effective|a sufficient[122] blanket, it is important to be aware that the gases readily blend with each other when moved. When trying to purge headspaces with inert gas, the determining factor in the purity of the final volume of gas is the gas’s flow rate as it exits the tubing. Higher flow rates lead to a churning effect that causes the oxygen-containing surrounding air to mix in with the inert gas. If this occurs, the inert gas’ ability to protect the wine is reduced because of its decreased purity. It is vital to be sure that the delivery method tries to avoid turbulence as much as possible in order to have a pure layer of inert gas that is lacking oxygen. The ideal flow rate needed to accomplish this is most often the lowest setting on your gas regulator. Usually, this means between 1-5 PSI, depending on the tubing size.

The second step to creating a protective inert gas blanket is to reach the highest volume of gas that can be delivered while still maintaining the low flow-rate required to avoid creating turbulence and hence mixing the gas with the air we are attempting to eliminate. While any size tubing can employed in the delivery of a sufficient inert gas blanket, the amount of time it calls for will increase as the delivery tubing diameter decreases. If you want to hasten the process of purging without compromising the gentle flow required to form a successful blanket, the diameter of the output tubing should be expanded. One easy way to accomplish this is to connect a small length of a larger diameter tube onto the existing gas line on your gas regulator.

The third and final step to effectively creating an inert gas blanket is to have the gas flow parallel to the surface of the wine, or laminar, instead of directing the flow of gas directly at the surface. This leads to the inert gas being less likely to blend with the surrounding air when being delivered because it will not bounce off the surface of the liquid. A feasible method to do so is to attach a diverter at the end of the gas tubing.

To put it all together, the recommended method for purging a headspace with inert gas is as follows: First, make the correct adjustments on the  gas regulator to determine a flow rate that is as high as possible while still maintaining a gentle, low-pressure flow. Then, place the tubing into the storage vessel and arrange it so that the output is close to the surface of the wine, around 1-2 inches from the surface is recommended. Next, turn on the gas and initiate the purging. Finally ,to check the oxygen levels, use a lighter and lower the flame until it is inserted just a little below the rim of the vessel. If the lighter remains lit, there is still oxygen in the vessel and you should keep adding the inert gas. Keep employing the lighter test until the flame eventually subsides, which will illustrate that the oxygen is gone.

Whether you’re looking for specialty gases to be employed in winemaking, other food and beverage applications, or any other industry that utilizes specialty gases, SYOXSA, Inc. has a plethora of products to meet all of the El Paso specialty gas needs. SYOXSA, Inc. has a large selection of specialty gases and specialty gas equipment, along with the resources and experts on hand in El Paso to answer your questions and assist your needs. For more information, browse our online catalog or contact us via email at Esteban.Trejo@syoxsa.com or at 915-771-7674.