Okay, ew… but for what it’s worth brewers yeasts are very specific strains of yeast that have been bred for the purpose. One of the most important aspects of these brewers yeasts versus regular bakers yeasts or wild yeasts (like a sourdough starter) is that they can thrive in higher alcohol environments, allowing them to convert more sugar into alcohol (e.g., I think champagne yeasts can give you a higher ABV). Brewers yeast will also likely be more efficient and convert sugar to alcohol faster than wild strains (sourdough is also a much slower process than using bakers yeasts), which might have implications for food safety if the yeast cannot outcompete other nastier microbes. You can make alcohol with wild yeasts but it’s not as controlled of a process.