Troubleshooting a sluggish or 'dead' sourdough starter

Almost certainly not. A sourdough starter is a hardy ecosystem - it survives weeks of neglect, accidental refrigeration, and most beginner mistakes. 'Dead' usually means dormant. The question to answer: is it producing CO2 (bubbles) and smelling tangy after a feed? If yes after 24-48h of effort, it's alive. If absolutely no activity after 3 days of warm, regular feeding, then yes - start a new one.

Feed it warm and let it sit. Discard until ~30g remains, add 30g whole rye + 30g 28°C water. Stir hard - oxygen helps. Place somewhere consistently 24-27°C (oven with light, top of fridge, near a heater). Wait 12 hours. If you see any bubbles or growth, you're back. Feed again, give it 12 more hours. By 24-48h you should have a doubling starter.

Chlorinated tap water suppresses wild yeast. Either filter it or let a jug sit out for 24 hours so the chlorine evaporates. A lid screwed on too tight builds CO2 pressure that can suppress activity (and occasionally pop). The fridge slows the colony to almost nothing - moving from fridge straight to a feed without a counter-acclimation step often looks like death (see how to store and revive from the fridge).

Pink, orange, blue, green, or fuzzy mould on the surface or in the jar. Persistent strong solvent / acetone smell that doesn't fade after 2-3 feeds. After a full 5-day rescue protocol, still zero activity. In all three cases, throw it out and start fresh - it's a one-week investment, not a heartbreak.

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