How Inert Gas Is Used in Winemaking

Several people have heard about the large number of applications that employ 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 frequently discussed is the utilization of specialty gases in an industry that directly involves nearly all people no matter their location- 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 some specialty gases actually are a significant factor in the process of making wine.

If a wine does not remain constantly protected from both oxygen and microbial spoilage during the aging process, it will most likely spoil. In order to safeguard the wine, it is vital to maintain satisfactory sulfur dioxide levels and keep containers full. Likewise, the extent of protection is considerably 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 employment in this process can be seen in a lot of winemaking literature. Yet, while these texts may touch on purging with inert gas, they usually do not efficiently explain the actual techniques required to carry out the application. First, it must be understood that it requires more than merely dispensing some argon into the headspace of your vessel in order to create a sufficient gas blanket to preserve your wine. The function of this article is to discuss the techniques needed to properly use inert gas to purge headspaces in order to successfully preserve your wine. First, we will detail the importance of safeguarding your wine from being exposed to oxygen, and after we will explain the precise gas purging methods needed to do so.

The space in a barrel or tank that is not filled by liquid is filled by gas. As is widely known, the air we breathe is a mixture of gases, about 20% of which is oxygen. While a constant supply of oxygen is crucial for humans, it is certainly not beneficial when it comes to the successful storage of most wines. The reason 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 unwanted flaws in the wine such as a reduction of freshness, browning, sherry-like smells and taste, and acidity production. Wines possessing theseunwanted characteristics are referred to as oxidized, since they occur upon exposure to oxygen. One of the key objectives in correct wine aging is learning the best methods to reduce the wine’s oxygen exposure in order to prevent oxidation. One easy method to do so is to fill the wine’s storage vessel as full as possible, in order to eliminate headspace. Nevertheless, this method may not always be feasible.

Unless you are storing your wine in a storage vessel that is guaranteed to keep the wine at a stable temperature, 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 iscompressed more easily than liquid, it does not add a lot of pressure the storage unit if there is some space left at the top. It is for this 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 an increase in temperature, it will expand and the resulting pressure will result in the full force of the liquid being pushed against the lid. In some extreme increases 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 lead to its spoiling. In an extreme temperature decline, on the other hand, the lids would be pulled inward as an effect of the liquid contracting. Thus, if there is a possibility that your wine could face temperature variations amid its storage, headspace should be left at the top of vessels.

While we now know we must keep a headspace, we still are left with the problem of leaving room for contraction and expansion while simultaneously 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 do not create negative reactions with the wine. In fact, carbon dioxide and argon are actually heavier than air, a property that proves advantageous to winemakers. Purging headspaces with either carbon dioxide or argon, when properly carried out, can get rid of oxygen by lifting it up and removing 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 effects during its storage/aging process. The key to correctly safeguarding the wine in this way is to be aware of the specific techniques needed for the successful creation of this protective blanket.

There are 3 steps suggested to create a protective inert gas blanket. The first step is maintaining purity by avoiding turbulence. When utilizing carbon dioxide or argon to generate [[a successful|an effective|a sufficient[122] blanket, it is essential to understand that the gases readily mix with each other when moved. When seeking to purge headspaces with inert gas, the gas’s flow rate as it exits the tubing acts as the determining factor in the purity of the final volume of gas. Larger flow rates generate a churning effect that causes the oxygen-containing surrounding air to mix in with the inert gas. In this scenario, the inert gas’ capacity to preserve the wine is decreased as a result of its decreased purity. It is vital to be sure that the delivery method makes effort to avoid turbulence as much as possible in order to have a pure layer of inert gas that has a minimum amount of oxygen. The ideal flow rate necessary to do this is generally the lowest setting on your gas regulator. Typically, this means between 1-5 PSI, depending on the tubing size.

The second step to generating a protective inert gas blanket is to reach the highest volume of gas that can be delivered while still maintaining the low flow-rate that is essential to avoid creating turbulence and hence blending the gas with the air we are attempting to eliminate. While any size tubing can employed in the delivery of an adequate inert gas blanket, the amount of time it requires will increase as the delivery tubing diameter decreases. If you want to speed up the process of purging without compromising the gentle flow needed to generate a successful blanket, the diameter of the output tubing must be increased. A simple way to achieve this is to connect a small length of a larger diameter tube onto the existing gas line on your gas regulator.

The third and last step to properly forming an inert gas blanket is to have the gas flow parallel to the surface of the wine, or laminar, instead of aiming the flow of gas directly at the surface. This results in 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 simple and correct method to do so is to attach a diverter at the end of the gas tubing.

To combine all the we have discussed, the suggested method for purging a headspace with inert gas is as follows: First, make the adequate adjustments on the  gas regulator to find a flow rate that is as high as possible while still maintaining a gentle, low-pressure flow. Then, insert the tubing into the storage vessel and arrange it so that the output is close to the surface of the wine, approximately 1-2 inches from the surface is best. Next, turn on the gas and initiate the purging. Lastly ,to check the oxygen levels, use a lighter and lower the flame until it enters the vessel just barely below the rim. If the lighter remains lit, there is still oxygen inside the vessel and you should keep inserting the inert gas. Keep employing the lighter test until the flame eventually subsides, which will reveal that there is no longer oxygen in the vessel.

Whether you’re looking for specialty gases to be utilized in winemaking, other food and beverage applications, or any other industry that utilizes specialty gases, ILMO Products Company has a plethora of products to meet all of the Springfield specialty gas needs. ILMO Products Company has a large selection of specialty gases and specialty gas equipment, along with the resources and experts on hand in Springfield to answer your questions and assist your needs. For more information, browse our online catalog or contact us via email at or at (217) 245-2183.