As an expert sommelier and brewer, I can confidently say that fermentation can indeed occur in orange juice without the addition of yeast. This is because fermentation is a natural process that can be initiated by the presence of bacteria and wild yeast that are present in the air and on the surface of fruits.
When it comes to fermentation, yeast plays a crucial role as it converts sugars into alcohol and carbon dioxide. However, it is important to note that yeast is not the only microorganism capable of carrying out fermentation. There are various strains of bacteria and wild yeast that can also initiate the fermentation process.
In the case of orange juice, there is a high likelihood that it contains naturally occurring yeast and bacteria. These microorganisms may have settled on the surface of the oranges during growth or may have been introduced during the juicing process. Therefore, even if you do not add any additional yeast, there is a good chance that fermentation will occur.
I have personally witnessed instances where orange juice has started to ferment on its own. In one particular situation, I had freshly squeezed orange juice sitting out on the counter for a couple of days. To my surprise, I noticed a slight fizziness and a tangy taste when I took a sip. This was a clear indication that fermentation had taken place.
The fermentation of orange juice without added yeast can lead to the production of various compounds, including alcohol, organic acids, and aromatic compounds. The specific flavors and aromas produced during fermentation can vary depending on the strains of yeast and bacteria present.
It is worth mentioning that the presence of wild yeast and bacteria in orange juice can also lead to spoilage if proper precautions are not taken. Therefore, it is important to store orange juice in a refrigerated environment to slow down the fermentation process and prevent the growth of harmful microorganisms.
To summarize, orange juice can ferment without the addition of yeast due to the presence of naturally occurring bacteria and wild yeast. This natural fermentation process can result in the production of alcohol, organic acids, and aromatic compounds, adding complexity to the flavor profile of the juice. However, it is essential to store orange juice properly to prevent spoilage and ensure its freshness.