How can a sourdough starter be 100 years old?

Question

I keep seeing sourdough starters all over socials. How can sourdough starters be many years old. Don’t you need to use the starter to make the bread? ELI5!

In: Other

Answer 1

you use a small piece of starter to make the dough for your bread, not the whole thing. you feed a starter daily by adding more flour and/or water as needed. this can go on for many years, as long as the starter is properly fed, and doesn’t get contaminated. it’s a colony of yeast microbes and the colony is effectively immortal as long as it stays healthy. individual yeast cells die, but there’s constant new cells being produced, so the colony continues.