As an expert sommelier and brewer, I can confidently say that juice cannot turn into alcohol without the action of yeast. Yeast is a microorganism that plays a crucial role in the fermentation process. When yeast comes into contact with sugars, such as those found in juice, it converts these sugars into alcohol and carbon dioxide through a process called fermentation.
Fermentation is a natural process that has been utilized by humans for thousands of years to produce alcoholic beverages. It is commonly used in the production of wine, beer, and even spirits. Without yeast, the sugars in juice would simply remain as sugars and not undergo any transformation into alcohol.
Yeast is naturally present in the environment, and it can be found on the skins of fruits, including apples. However, the amount of yeast present on the surface of fruits is usually not sufficient to initiate a significant fermentation process. Therefore, if you were to leave a bottle of apple juice sitting out without any added yeast, it is unlikely to ferment and turn into alcohol.
That being said, there are some rare instances where juice can ferment naturally without the addition of yeast. This can occur if the juice is exposed to wild yeast strains that are present in the air or on the surfaces of equipment used during the production process. However, these occurrences are relatively rare and difficult to control.
In commercial settings, juice is typically pasteurized to kill off any yeast or other microorganisms that may be present. This ensures that the juice remains stable and does not ferment. Pasteurization involves heating the juice to a specific temperature for a certain period of time, effectively killing off any microorganisms.
If you are interested in fermenting juice into alcohol, it is important to add a suitable yeast strain to initiate the fermentation process. There are different types of yeast strains available, each with their own characteristics and suitability for specific types of beverages. Adding yeast allows for greater control over the fermentation process, ensuring that the desired alcohol content and flavors are achieved.
Juice cannot turn into alcohol without the presence of yeast. Yeast is essential for the conversion of sugars in juice into alcohol through the process of fermentation. While there may be rare instances where juice can ferment naturally without added yeast, these occurrences are not common and difficult to replicate.