How long does the first stage of lambic fermentation typically last?

The first stage of lambic fermentation typically lasts about 3 to 7 days, which is why this answer is considered correct. During this initial phase, spontaneous fermentation begins as wild yeasts and bacteria present in the environment start to convert the sugars in the wort into alcohol and carbon dioxide. The fermentation process is unique to lambic beers, as it relies on natural inoculation rather than cultivated yeast strains.

Although fermentation may show signs of rapid activity within this timeframe, the environment and temperature can also influence the exact duration. After these initial days, there will often be a transition to more complex fermentation activities that involve various microorganisms contributing to the beer's distinctive flavor and character.

Other timeframes provided in the options don't accurately reflect the timing typical of this spontaneous fermentation process. Therefore, selecting the 3 to 7 day range aligns with industry practices for lambic production.