As an experienced sommelier and brewer, I can tell you that the length of time it takes for cider to ferment naturally can vary. If you are relying on the naturally occurring wild yeasts in apples, it may take one or two weeks for the fermentation process to get underway. During this time, the yeast will consume the sugars in the apple juice and convert them into alcohol.
However, it's important to note that the presence of wild yeasts can be unpredictable. Factors such as the quality and ripeness of the apples, the temperature of the fermentation environment, and even the specific location where the apples were grown can all affect the fermentation process. In some cases, the wild yeasts may not be strong enough or present in sufficient quantities to initiate fermentation.
If you have waited for two weeks and there is still no sign of fermentation, it may be necessary to add a cultured yeast to kickstart the process. One popular option is Vigo Presses cider yeast, which is a high-quality cider yeast commonly used by commercial producers. This cultured yeast is specifically selected for its ability to ferment apple juice and produce a desirable flavor profile in the resulting cider.
I have personally used Vigo Presses cider yeast in my own cider-making endeavors and have found it to be reliable and effective. When adding a cultured yeast, it's important to follow the manufacturer's instructions for rehydration and pitching. This will ensure that the yeast is able to thrive and ferment the apple juice properly.
The time it takes for cider to ferment naturally can vary depending on the presence and strength of wild yeasts. If no fermentation occurs after two weeks, adding a cultured yeast such as Vigo Presses cider yeast can be a good solution. However, it's always important to be patient and allow the fermentation process to run its course, as the flavors and aromas of the final cider can develop over time.