Wine is an alcoholic beverage made from fermented grapes. Non-alcoholic wine is an non-alcoholic beverage made from alcoholic wine, (Wow, some hard-hitting factoids coming your way.) But how is non-alcoholic wine made exactly?
Let’s look at how winemakers take traditional wine and remove the alcohol from it.
The basics of winemaking
Before we dive into the specifics of non-alcoholic wine production, let’s just remind ourselves of the basics of winemaking. Winemaking involves several steps, including harvesting the grapes, crushing them, and fermenting the resultant juice with yeast. The two primary types of yeast used in winemaking are natural or wild yeast (naturally occurring on the grape skins and in the winery) and cultivated yeast strains. Cultivated yeast strains are often chosen because they offer more predictable fermentation and can enhance specific wine characteristics. The yeast consumes the sugars in the must and converts them into alcohol and carbon dioxide.
During alcoholic fermentation, yeast cells break down the sugar molecules in the grape juice, primarily glucose and fructose, into ethanol (alcohol) and carbon dioxide. This process can take anywhere from several days to a few weeks. The speed depends on factors like temperature, yeast strain, and the desired style of wine. Once the fermentation process is complete, the wine is aged and bottled.
The challenge of making non-alcoholic wine
The challenge of making non-alcoholic wine lies in removing the alcohol while preserving the flavour and aroma of the wine. There are several methods for de-alcoholising wine, each with its own advantages and disadvantages. Some methods involve removing the alcohol after fermentation. Others involve stopping the fermentation process before all the sugar is converted into alcohol.
Methods for making non-alcoholic wine
Reverse osmosis
Reverse osmosis involves passing the wine through a semi-permeable membrane that separates the alcohol from the water and other compounds in the wine. During osmosis, molecules of a solvent (in this case, wine) pass through the membrane from a less concentrated solution into a more concentrated one. As a result, the concentrations on both sides of the membrane equalise. The membrane allows the passage of small molecules but prevents the passage of larger molecules, such as those in the alcohol. Reverse osmosis is often used in desalination plants to remove the salt from seawater.
Spinning cone column
This technique calls for heating the wine and then passing it through a series of rotating cones that operate at high speeds. These dynamic cones effectively separate the alcohol from the other constituents in the wine, resulting in a non-alcoholic wine. What makes the spinning cone method particularly appealing is its gentle approach, as it doesn’t rely on harsh chemicals or excessive heat, which can compromise the wine’s delicate flavour and aroma-producing compounds. Additionally, it empowers winemakers with precise control over alcohol content, an important factor for compliance with diverse regional regulations.
Vacuum distillation
Vacuum distillation is a method that has garnered acclaim in non-alcoholic winemaking. It works by heating the wine in a vacuum, which lowers the boiling point of alcohol. This enables the separation of alcohol from the rest of the wine. A significant advantage of vacuum distillation is its ability to preserve a more comprehensive spectrum of the aroma and flavour compounds that contribute to the appeal of wine. The process employs lower temperatures, minimising the loss of volatile compounds. Furthermore, vacuum distillation can be tailored to selectively remove a portion of the alcohol. This enables the creation of low-alcohol or reduced-alcohol wines, as well as entirely alcohol-free versions.
Fermentation techniques
hese techniques focus on controlling the production of alcohol during fermentation. One method involves stopping the fermentation process before all the sugar is converted into alcohol. This yields a slightly sweeter, non-alcoholic wine. Another strategy revolves around the use of specialised yeast strains that produce lower amounts of alcohol during fermentation, thereby ensuring a reduced alcohol content in the final product. This approach is akin to “preventing the horse from bolting,” as it curtails the alcohol production at an earlier stage in the winemaking process.
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The process of making non-alcoholic wine involves removing or reducing the alcohol content while preserving as much of the flavour and aroma of the wine as possible. As techniques become more refined and malleable by winemakers, the flavour, aroma of non-alcoholic wines will become more and more complex.
Image credit: Nacho Domínguez Argenta