Is My Sourdough Starter Dead? How to Revive a Dormant Culture

Let’s make some dough!
They're very likely not dead — just slow. Here's why.
A healthy starter carries roughly 200 million LAB (lactic acid bacteria) per gram, and about 10 million wild yeast per gram. Cold doesn't kill that population — it slows it way down. Both go dormant, and the hooch/acidity on top actually help protect what's left rather than harm it.
Here's the numbers worth sitting with. Even at 95% die-off — a realistic case for what 2 years actually does — you'd still have about 10 million live bacteria and 500,000 live yeast in every gram. Push it to an extreme 99.9% die-off, and you'd still have roughly 200,000 LAB and 10,000 yeast per gram. Either way, that's a real, feedable population. After 3-6 days of consistent feeding and you will be well on your way to a complete rebuild.
And here's the part that should take the pressure off completely: even in the true worst case, where everything in that jar actually did die, what you're feeding it with — the flour itself — carries its own wild yeast and bacteria straight off the grain. That's literally how a starter gets built from nothing, and that is information that most bloggers don't talk about. So, if you fed it for 6 days and worst case, you're feeding a completely sterile culture — you're likely already halfway to building your own brand-new starter.
Two months or two years dormant, — the math holds. Feed it consistently, give it days rather than hours, and judge it by volume, bubbles, and smell.
Until next time, let's give thanks for our daily bread…
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