Non-alcoholic wines go through the same winemaking or vinification process of crushing, fermentation and aging that regular alcoholic wines go through. However, one last step is introduced to remove the alcohol from the wine — a process known as dealcoholization.
The Vinification Process
Generally, winemaking follows the three steps explained below. The process is the same for non-alcoholic and regular wine.
1. Harvesting and Crushing
The vintner or winemaker harvests the grapes from the vineyard, separates the fruits from any leaves or vines and crushes or presses the fruits to get the grape juice. The substance obtained is called a must.
2. Fermentation and Alcohol Formation
Depending on whether the vintner is making red or white wine, they may remove any seeds, skin and stems from the grape juice. These items produce the most tannins, which are responsible for the dryness of a wine. For red wine, the winemaker leaves the seeds, skin and stems to ferment with the grape juice, but for white wine, the winemaker separates these items out.
Then the vintner leaves the wine to ferment. In the process of fermentation, yeast converts the sugar content in the grape juice to alcohol to produce the wine. The vintner adds different types of yeast depending on the flavors they want to achieve. The wine ferments for as long as the winemaker wants. For example, if they want to reserve some sweetness to the wine, they stop the fermentation early, before all the yeast eats all the sugar. For a drier wine, the grape juice sits through the complete fermentation process until the yeast has converted all the sugar into alcohol.
The fermentation process typically starts between six and 18 hours after the grapes are crushed and can last for one or more months based on the amount of alcohol the winemaker wants. Once fermentation is complete, the wine can contain as much as 14% alcohol by volume (ABV).
The process of fermentation also produces different aromas, flavors and tastes in the wine, which together are called the wine’s bouquet. The alcohol typically carries most of a wine’s bouquet.
3. Aging and Maturation
To change the bouquet of the wine, some winemakers leave the wine to mature in a process called aging.
Vintners age wine by putting it into oak barrels, stainless steel tanks or bottles and leaving it to mature. The process of maturing introduces new aromas and flavors and balances the wine’s taste. The tannins and the body of the oak barrels also contribute to the aging process of the wine.
Aging can take as long as the winemaker needs to get the needed taste and texture. These factors are also called the mouthfeel and the physical characteristics of the wine in the mouth. For white wines, aging is typically not more than a few months, while aging often goes for 18 to 24 months for red wine. Besides the addition of grape skins, the duration of aging and the presence of tannins is the major difference between how white wine and how red wine is made.
Fermented grape juice intended for non-alcoholic wine can also undergo aging. This process is why most non-alcoholic wines can possess the same flavor and mouthfeel as regular alcoholic wine. For example, the Sutter Home Fre White Zinfandel possesses the same body and dryness as its regular alcoholic counterpart.
For regular wine, the process ends here. The vintner bottles the wine and ships it off. For non-alcoholic wine, the wine goes through one more step to remove the alcohol called dealcoholization.
The Alcohol-Removing Process
There are several different ways of removing or separating alcohol from wine — or from any fluid at all. The process of separating alcohol from wine was first invented at the end of the 20th century. However, the process has since undergone a lot of improvements and modifications.
Since alcohol transports a lot of a wine’s flavors, the major challenge of dealcoholization is removing the alcohol without destroying, removing or altering the flavors, aromas, tastes, mouthfeel, balance and overall quality of the wine. Based on how precise the dealcoholization process is, there might still be a small fraction of alcohol left in the wine. Generally, non-alcoholic wines contain below 0.5% ABV. The very fine non-alcoholic wines can have 0.05% alcohol and sometimes — but rarely — 0.0% ABV.
Here are the three most common dealcoholization processes.
1. The Distillation Method
When using the distillation method, the winemaker heats the wine to a high temperature to evaporate the alcohol from the wine. For this to work, the mixture must be heated to the boiling point of ethanol, the specific type of alcohol present in wines. Ethanol boils at 176 degrees Fahrenheit.
However, the problem with this high-temperature method is that some of the flavors and aromas in the wine can also evaporate or change through a process called oxidation. This can greatly affect the quality, taste and flavor of the final product.
To combat oxidation, winemakers heat the wine in a closed and airtight space or a vacuum. In a vacuum, the boiling temperature of ethanol drops to 80 degrees Fahrenheit. At this temperature, the alcohol evaporates, but the flavors and aromas in the wine stay intact. Distillation in a vacuum removes the alcohol but preserves the other qualities of a wine. Additionally, the alcohol can be collected and reused for other purposes.
2. The Reverse Osmosis or Filtration Method
Instead of heat, the reverse osmosis method uses pressure and a membrane to separate the alcohol from the wine.
The reverse osmosis method uses a very thin membrane or filter to separate alcohol from the rest of the wine. With this method, the winemaker pushes the wine mixture through a filter at high pressure. The holes in the membranes are so small that only alcohol and water molecules can pass through. The alcohol and water mixture is collected on one side of the filter, leaving the concentrated non-alcoholic wine on the other side. The winemaker then uses distillation to separate the alcohol from the water and adds the water back into the wine concentrate.
3. Spinning Cone Method
The spinning cone method uses a column of cones placed in a centrifuge to separate the alcohol from the wine.
Using this method, the winemaker puts the wine into the cones in the centrifuge and spins the centrifuge at a very high speed. This movement creates a centrifugal force that separates the wine into thin layers. The winemaker then introduces nitrogen gas into the cones to remove all the aromas and other wine components, leaving the water and alcohol in the cones. To separate the water from the alcohol, the winemaker spins the cones again at a higher temperature, then adds the water back to the wine.