By: Gerald Dlubala
There are as many secrets and tricks of the trade-in producing great tasting wines as there are winemakers. But most winemakers can agree that the use of nitrogen is key to the process. Nitrogen application within the winemaking process can be used in every phase of production through dispensing in a tasting room. It is suitable for use in tank blanketing, equipment purging, pump and filter membrane testing, pressure transfers, must lifting and even with centrifuge use. Nitrogen’s predominant use, however, is still in the container filling function. By introducing nitrogen during the bottle or can filling process to displace the natural oxygen present in the headspace of the containers, the winemaker can better control oxidation, the chemical reaction that can significantly change the consistency, flavor and bouquet of the wine while in its container.
By controlling the oxidation rate, the shelf life of the wine is significantly extended. And with today’s consumer seeking more convenient packaging choices, the inherent usefulness and benefits of liquid nitrogen dosing increases.
Convenience Packaging Increases Need For Nitrogen Dosing
“Nitrogen dosing is almost a must in today’s marketplace and will likely remain useful and important for the foreseeable future,” says Jim Fallon, Application Engineer for Vacuum Barrier Corporation, a complete one-source provider of custom and standard liquid nitrogen (LN2) solutions for all applications.
“When you talk in general terms, there are continuous discussions regarding the reduction of waste and the movement to more recyclables in our environment,” says Fallon. “Realistically, in today’s market, that means more of a movement to aluminum as a more convenient, recyclable, environmentally friendly container for many rigid packaging applications. And in the case of wineries, that means an increase in aluminum can packaging. So now, in addition to the need for oxygen reduction, you’re talking about the need for adding pressure for container stability. Nitrogen dosing addresses both of these issues. The distributed dosage amount is fully customizable, being dependent on the amount of air that is left in the headspace of the container to be filled and where the in-line dosers are located with respect to the sealing, capping or corking operation.”
Vacuum Barrier Corporation provides complete liquid nitrogen dosing systems, including all the necessary piping from the nitrogen supply through the doser that dispenses the nitrogen in liquid drop form. Using nitrogen in liquid form has shown to be more economical than standard gaseous use. The liquid droplets expand by 700x their volume, so a little goes a long way in pressurizing packages and purging headspace. By dispensing the nitrogen in a liquid state for dosing, it allows the nitrogen droplet to immediately fall to the bottom of the headspace before the rapid transition to its gaseous state, subsequently pushing the oxygen out. Regarding aluminum cans, that transition to gas also provides the necessary pressurization immediately before the seaming process to provide can stability and rigidity. When wineries choose to replace corks with screw caps, they add a little more headspace in the bottle that must be purged, affecting dose size. The entire liquid to gas transition and capping/seaming can take a second or less, so dosing amount and timing are critical.
While dosing systems can become one of the most important systems in the packaging process, Fallon tells The Grapevine Magazine that nitrogen storage and auxiliary equipment are equally important to the process, and like the dosers, must be properly fitted to the needs of the end-user.
“Storage vessels are generally available in two forms, larger bulk tanks or the smaller portable units called dewars. Bulk tanks are normally outside installations while the portable dewars are kept inside and located closer to where they are used. Both designs generally feature a double-wall construction with a vacuum space sandwiched between the two walls. That allows the tank’s outside surface to remain at the ambient temperatures while the inner space will be able to hold the proper cryogenic temperatures. To combat against any bit of temperature loss, insulated piping, using that same vacuum design, is recommended to maintain efficiency.”
Sizing Your Dosing System To Your Needs
Chart Industries is a recognized leader in the design and manufacture of cryogenic equipment used from beginning to end in any liquid gas supply chain. Their liquid nitrogen dosing systems and cryogenic storage units are some of the most relied on throughout the wine industry.
“Nitrogen dosing is done simply for oxygen reduction in the winemaking and bottling process,” says Tyler Jones, Product Manager of Dosing Systems for Chart Industries. “But the added benefits that come with nitrogen dosing include improved shelf life with better ability to maintain the integrity of the product as it ages. Everything ages, but not everything ages well, or properly. By dosing with nitrogen, we allow the wine to age well AND properly, staying true to the flavor profile that the winemaker came up with and intended for you to experience. Nitrogen dosing simply leads to a better product with a truer flavor. The doser is fitted in between the filler valve and cappers/corkers, delivering a single drop of measured liquid nitrogen that then expands 700x its volume during the transformation from liquid to gas. That’s enough to remove all other gases occupying that same space, effectively reducing the total package oxygen.”
Chart Industries documented data on liquid nitrogen dosing suggests that extended shelf-life studies show a 90-95% reduction in headspace oxygen content and a 59% reduction in total package oxygen when compared to a traditional gas purge of headspace.
Juancho Tabangay, Director of Sales – LN2 Dosing for Chart Industries, tells The Grapevine Magazine that their main focus is installing the properly sized liquid nitrogen dosing systems and storage for each customer they work with.
“There is no one size fits all,” says Tabangay. “We can provide a vast range of storage and dosing options throughout many industries, so what is best for a particular winery ultimately depends on their specific nitrogen use and overall consumption needs. You don’t want your nitrogen supplier to have to deliver to you more than once a week, so we’ll properly size each part of the nitrogen storage, delivery and dosage system to meet that goal.”
Chart Industries is the first to provide a complete turnkey liquid nitrogen dosing system, from dosers, valves, piping, phase separators on to bulk storage options. They are the world’s leading single-source liquid nitrogen equipment and solutions provider across the whole liquid nitrogen chain from initial liquification through end-user dosing. Their equipment allows for high quality, low pressure nitrogen on demand resulting in a consistent, continuous supply of unsaturated liquid nitrogen. And while nitrogen use in winemaking is generally used for preservation, Tabangay says that nitrogen dosing is also a very efficient way to pressurize a variety of packaging, use in freezing applications like the trendy nitrogen ice cream, and to use in modified atmosphere packaging for coffees, nuts, formula, etc. And we all know how good those nitrogen dosed coffees and beers are.
Being a complete turnkey system supplier, Chart Industries provides a full line of storage solutions based on your total consumption needs and flow requirements, providing tanks ranging from portable dewars to the largest bulk storage tanks. Their standard cryogenic tank is considered the industry workhorse, able to be customized when needed to fit any situation. They’re available in insulated horizontal or vertical configurations ranging from 524 to 264,000-gallon capacities, making them a reliable storage solution with reduced maintenance and low cost of ownership. Chart’s bulk storage tanks feature pearlite insulation or their own proprietary vacuum Composite Super Insulation system, making for a lightweight tank with high thermal performance and extended hold times while featuring reduced operational and installation costs.
When It Comes To Nitrogen Use In Wineries, Size Doesn’t Matter
The Cave Vineyard and Distillery, located in picturesque St Genevieve, Missouri, uses the smaller, portable dewars in their winery operation. Marty Strussione, winemaker and owner, keeps four 50-pound nitrogen-filled dewars on-site at all times. Two of them are always in use and the other two are spares.
“We use nitrogen two ways,” says Strussione. “We first use nitrogen for purging the oxygen out the bottles while they’re still empty, and then we also use it immediately before our capper to get the remaining oxygen out of the headspace before the bottle gets sealed.”
On rare occasions, Strussione will use nitrogen to top off his tanks when needed, but that’s generally done with CO2.
“I do think about different ways to handle the nitrogen supply, maybe something more convenient,” says Strussione. “But being a smaller winery, it’s just a matter of cost. We currently only put out about 20,000 bottles a year, so I can’t justify adding a bulk tank or onsite nitrogen generator right now. We do make use of an ozone machine, but that’s about the extent of it.”
At the other end of the spectrum is Augusta Winery, a multiple international gold and silver award winner located in Augusta Missouri. Owner Tony Kooyumjian says, “We use nitrogen in all phases of our winemaking because each step in the process presents the opportunity to allow a certain amount of oxygenation, so the more of these opportunities that we can control, the better.”
Kooyumjian uses nitrogen for both the bottle purging and reduction of headspace oxygen functions, but also in all of the lines to reduce the oxygenation occurring during liquid transfers. He was using so much nitrogen throughout the winery that over ten years ago he decided to purchase and install his own nitrogen generation system on-site to produce nitrogen on demand. While being costly upfront, Kooyumjian said that the system paid for itself within about three years. By doing it this way, his award-winning wines retain integrity, flavor and aroma with increased shelf life.