A question often asked in the wine and grape industry is: which is better for wine production, nitrogen or argon? Both are inert gases at room temperature, and both are used for blanketing wine and flushing or purging tanks.
There are also some key differences:
- Argon is about four times more expensive than nitrogen because there is less of it in the air (79 percent of air is nitrogen, compared to 0.9 percent for argon).
- Argon is about 1.4 times denser than nitrogen.
- Argon can only be provided in tanks, whereas nitrogen can be supplied through in-house gas generation.
Heavier isn’t always better
Argon’s density can be misleading. Because it is heavier than air, many winemakers assume that it will stratify when added to the headspace of a tank and remain there, intact and unchanging. This, however, isn’t true.
Argon, being an ideal gas, will readily mix with air through a process called molecular diffusion, which breaks down this stratifying effect. Imagine someone opening a bottle of ammonia on the far side of the room and in a minute or two you can begin to smell it—this is molecular diffusion in action.
Gravity only has a slight tendency to concentrate heavier gas. Since argon is so expensive, wineries using it tend only to top off—typically three times per week—and don’t really know how quickly the argon disperses. Because other molecular forces are at work, argon will diffuse over time, weakening its blanketing abilities and leaving the wine vulnerable to oxidation.
Nitrogen is the best way to blanket
Since argon is more expensive than nitrogen and does not protect wine more effectively, it makes economic sense to use nitrogen instead of argon. It is even more cost-effective to generate your own nitrogen, in-house, from compressed air using a nitrogen gas generator. Some of the benefits of in-house nitrogen generation include:
- Elimination of vendor management issues such as price increases, contract negotiations, inflexible delivery schedules, tank rental fees, and delivery fuel surcharges.
- A reliable gas supply – no need to worry about a shortage of gas, especially when production suddenly increases.
- No safety risks from heavy, dangerous high-pressure cylinders.
Nitrogen is also widely used in other industries for protective purposes. For example, in food processing, nitrogen is used to blanket edible oils to prevent rancidity, and in chemical processing, it is used to blanket chemicals to prevent explosions. An in-house nitrogen gas generator will inexpensively blanket wine with a steady flow of nitrogen, resulting in low dissolved oxygen in the wine.
A Parker Balston WineMaker Series nitrogen generator, for instance, provides an unlimited supply of 99.9 percent pure nitrogen for blanketing wine and purging tanks. WineMaker Series nitrogen generators are “plug-and-play” systems that can be easily sized to meet any production needs. Return on investment is approximately one year—after that point the cost of supplying nitrogen is only routine maintenance that is easily done by staff (filter and O-ring replacement) and the electricity the generator consumes.
"Our customers are thrilled to produce their own nitrogen on-site. Gone are the days of dealing with ordering gas, dealing with polluting diesel delivery trucks coming to their vineyard, or handling heavy cylinders. Parker is pleased to support hundreds of wineries both in the Napa Valley and around the globe."
David Connaughton, product manager, Parker Hannifin Gas Separation and Filtration Division
This video features winemakers discussing the benefits of using an in-house nitrogen gas generator.
This post was contributed by David Connaughton, product manager, Parker Hannifin Gas Separation and Filtration Division.
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