Eli5: How did humans first manage to collect the bacteria used for fermentation?



Like acetic acid bacteria

In: Biology

Answer is- they grow EVERYWHERE. the trick is getting the ones that are good to out grow the ones that are bad. Once a family had this(and they had no idea), they sort of continued to have it. An exmple is a family that has a special “stiring stick”. When the stir the booze it works and when they dont, it dosent. The stick itself has groves and holes where the bacteria grow and they unknowingly inoculate it. Im assuming you meant ferment as in beer.

Great question. First they noticed the bacteria growing naturally in alcohol and other fermented products, then they captured the bacteria in petri dishes and cultivated it until it was suitable.

bacteria and mold are everywhere. you’re breathing it right now. if you left a glass of water on the counter, it’ll have mold spores in it sooner or later. that’s how we found them. leave water or dough out. some bad molds, some good molds

When you say bacteria, do you mean yeast?

Because yeast is everywhere. You can make a sourdough starter super easily at home. The people would make unleavened bread dough, and if it was left out, yeast would go to it. Then they continued to use that dough (generally just scraping the bowl at the end of making bread and keeping that leftover to add to the next time they made bread). Alcohol was the same thing, they just left out their drink and yeast would go to it

It is oftentimes naturally present. For example, sauerkraut is made by chopping cabbage and salting it. You don’t need to add any bacterial cultures. This bacteria is already there on the cabbage, you just need to prepare an anaerobic environment to let it do its work.

They just left things sitting out. Seriously. The yeast and bacteria that cause fermentation are in the air. Originally, when they left stuff out, some would spoil, and some would ferment. It depends on which yeasts and bacteria’s take over. Once you have one that ferments successfully, you can keep a small portion of the fermented food and add it to unfermented food to cause that food to ferment. People do this to this day for things like sourdough bread starters, cheese cultures, fermented vegetables (like sauerkraut), and more. As long as you keep using the culture to make more fermented foods, it will usually continue to work.