Alcohol-free wine, that doesn't sound very good at first. After all, alcohol is part of the wine. Or not? And what happens when you take him out? And how do you even do that? Today we are devoting ourselves to these questions and other questions on the subject of non-alcoholic wine.
Non-Alcoholic Wine - Does that grow on the vine?
Before we get into medias res, a short detour into wine law. Because here it is precisely defined when wine can be described as non-alcoholic. Namely, if the alcohol content is below 0.5%.
If you let nature take its course, then wine always has alcohol. Because it is created automatically during fermentation . Yeasts metabolize the sugar contained in the grapes and convert it into alcohol and CO². The level of alcohol content depends on the sugar content of the grapes at harvest. The more sugar there is, the more potential alcohol can form.
This process runs until one of the following three scenarios occurs. On the one hand, the fermentation stops naturally when the sugar has been completely converted, since the yeast then have no more food. In addition, the process can also stop when a certain threshold of alcohol is reached in the wine. Because from approx. 16 vol.% alcohol in the wine the yeasts die off. And the final reason for ending fermentation can of course also be provided by the winemaker, who can also stop the process from the outside. For example, by lowering the fermentation temperature so much that the yeasts are too cold to work. Or by separating the wine from the yeast as he wants to keep a certain level of residual sweetness in the wine. Non-alcoholic wine can therefore not be produced naturally. But how do you get him out?
How non-alcoholic wine is made
If you want to dealcoholize wine, you are faced with several challenges. On the one hand, of course, you only want to get the alcohol out of the wine, but not the aromas. So here it is important to proceed extremely gently in order to preserve the taste and remain as close as possible to the original. On the other hand, the basic composition of the wine naturally changes as a result of the dealcoholization. For example, if you get the alcohol from a previously 15% wine, then these 15% are missing. This means that all other components are proportionally proportioned. In sensory terms, this is particularly noticeable in relation to the acidity. Of course, this does not actually change, but is now dissolved in 15% less total mass and tastes correspondingly stronger. For this reason, non-alcoholic wine tastes a little different than traditional wine, of course - but just as good. But back to the question of how to get the alcohol out of the wine in the first place.
The vacuum distillation
Vacuum distillation is the most common process when producing non-alcoholic wine. Here, the alcohol is removed from the wine by gentle heating. One makes use of an observation made by Carl Jung at the beginning of the 20th century. Namely, the boiling temperature of alcohol in a vacuum drops to 27-30°C. So, by gently heating the wine, the alcohol will evaporate sooner than the other components. Pretty handy, right? The advantage of this gentle process is that the aromas of the base wine are largely retained. However, it is quite complex and also expensive due to the increased energy costs.
The reverse osmosis
Reverse osmosis is a filter principle that is a bit reminiscent of making coffee. The wine is pumped through an extremely fine-pored membrane that is impermeable to the alcohol and thus holds it back. In order to achieve the alcohol content of less than 0.5 vol.% required for labeling as non-alcoholic, this process has to be repeated several times. It is therefore time-consuming, but very gentle on the aroma of the wine.
Centrifugal Cone Column Process
Admittedly, the name of this method is not exactly catchy. In terms of content, however, it is fortunately easier to understand. This process also takes place in a vacuum. The wine is divided into its components by rotating cone plates using centrifugal force. The process originated in Australia and was initially used to produce non-alcoholic beer. But alcohol-free wine can also be produced in this way. However, as you can easily imagine, this procedure is not particularly gentle. It adds quite a bit to the wine.
As you can see, there are different ways to dealcoholize wine, all of which have their advantages and disadvantages. We mainly work with vacuum distillation for dealcoholization, but we have also carried out very promising experiments with reverse osmosis. We will keep you informed when there are new results.
