Winemaking has come a long way since folks were stomping on grapes and dumping the resulting juice into whatever vessel they had around. Over the last few centuries, the industry has become increasingly sophisticated, resulting in wines that are more consistent and more reliably delicious from vintage to vintage.
To learn more about how winemaking is evolving in Pennsylvania, we asked Molly Kelly, a full-time educator with Penn State Extension, to share some of the latest technological advancements in viticulture and enology.
Juice Clarification by Flotation
When white wines are pressed, the murky juice that comes out contains solids, which typically need to be removed before fermentation. In the traditional method, “cold settling,” the solids naturally sink to the bottom. This process is long and the wine must be chilled to prevent the start of fermentation (an expensive energy drain). Enter: flotation (also called “reverse settling”) an innovation that speeds up the clarification process. Grape solids are separated using nitrogen gas or air bubbled from below under pressure. When the bubbles rise, they take the solids with them. They can then easily be skimmed off the top.
Non-Saccharomyces Yeasts for Fermentation
This family of yeasts was long considered a contaminant in winemaking and brewing, and labeled as “spoilage yeast.” But when employed properly, it turns out they alter the chemical composition of the wine during fermentation, helping create intriguing — and desired — flavor compounds and enhancing the aroma profile of the wine. These yeasts are an exciting new set of tools for winemakers looking to toy with different styles.
Many traditional winemaking strategies, including barrel aging, allow small amounts of oxygen into the wine. This term describes the controlled addition of oxygen using a two-chamber machine. Oxygen, which impacts the color, bouquet, and mouth-feel of the finished wines, is injected into the wine via a porous ceramic stone. The technology takes a process that often takes months and turns it into one that is quicker and more precise.. This is especially useful when it comes to reds: Young wines can acquire complexity and character — and be ready to hit the shelves — in a shorter time frame.
Packaging: Canned Wines and Plastic Bottles
Wine has been contained and sold in glass bottles for centuries. Glass is strong and airtight, but it is also heavy. Modern packaging innovations, including aluminum cans and plastic bottles, help bring down shipping costs and make wine more portable for consumers.
Accentuated Cut Edge (ACE) Maceration
Winemakers often seek to increase the tannic punch of a red wine. Dr. Angela Sparrow at the University of Tasmania had an idea. Tannins come from grape skins, and she hypothesized that most of those tannins are released via the cut edges of the skins. Her solution: more cut edges. She developed a special machine that slices up grape skins right after crush, and has proved via blind taste tests that “ACE maceration” improves flavor, color, and tannic heft.
Field Picking and Destemming Machines
The technology in automatic grape picking machines has come a long way in the past few decades, allowing growers more flexibility when it comes to staffing and the ability to quickly pluck fruit at peak ripeness. Now those machines are being joined in the field by destemmers. This means that, by the time the load gets back to the winery, the crates hold nothing but perfect orbs — or as some in the industry call it, “Cabernet Caviar.” This streamlines the harvest process.
Inert Gas Vacuum Pressing Technology
Today’s high-tech grape presses employ inert gas — typically nitrogen — to create a protected environment for the must (a term for freshly crushed juice and skins). By flooding the space with nitrogen, oxygen is prevented from interacting with the wine during this sensitive time. Studies have shown that preventing oxygenation can increase the acidity and up the aromatic compounds of the resulting wines. This intervention is especially effective with white wines and rosés.
The future holds even more potential for innovation, including optical sorters (a machine that uses LED lights to separate perfectly ripe grapes from diseased or desiccated fruit; the duds are bumped into a discard hopper using a puff of air), hybrid barrels for aging (typically made with a stainless steel body, a wood head for micro-oxygenation, and an internal structure for holding flavor-imparting staves of wood), and more advanced lab testing (which will guide harvest decisions and identify spoiling agents). All exciting stuff!
As you can see, while the basic formula for wine — grapes plus yeast plus time — remains the same, the ways winemakers get there is constantly evolving, both here in PA and across the globe.