Why Is My Sourdough Starter Not Rising? (and How to Fix It)

Before you blame the starter, rule out the most common false alarm: it rose and fell while you weren't looking. A healthy starter can double and collapse back in four to six hours when it's warm, so if you only check morning and evening you'll see a flat jar both times and assume nothing happened. Put a rubber band or a mark at the level right after feeding and check every hour or two. If it climbs at all between feeds, it's alive and you just need to catch it at peak.

This is exactly what logging solves. If you note the feed time and the level each time you look, the rise-and-fall curve becomes obvious within a day or two, and you'll know your starter's real peak window instead of guessing. Sourdough Tracker does this for you and tells you when it's at its best for baking.

Temperature is the single biggest lever on how fast a starter rises, and most kitchens are colder than the bugs want. Below about 20 C a starter slows right down; below 15 C it can look completely dormant even when it's perfectly healthy. If your starter doubles in eight hours in summer but barely moves in a cold winter kitchen, temperature is your answer, not death.

Find a warm spot: on top of the fridge, near (not on) a radiator, in the oven with just the light on, or in a turned-off microwave next to a mug of hot water. Aim for 24 to 28 C and give it time. See the temperature guide for the full picture.

A starter eats its food quickly. If you feed it a tiny amount, or feed it on top of a big existing mass without discarding first, the fresh flour is gone almost immediately and there's nothing left to power a visible rise. The fix is a clean, generous feed at a proper ratio: keep a small amount of starter and feed it equal weights of starter, flour and water (1:1:1), or 1:2:2 if your kitchen is warm and it's outrunning you. Weigh it, don't eyeball it.

A reliable reset: keep about 25 g of starter, add 50 g flour and 50 g water, and a healthy culture should roughly double in 12 to 24 hours. If it's been neglected, two or three twice-daily feeds in a row will usually bring it roaring back. Our feeding guide walks through the ratios.

A brand-new starter from scratch is not supposed to rise reliably yet. There's often a burst of false activity on days two to four (driven by bacteria you don't actually want), then a discouraging quiet spell for several days while the real yeast establishes itself. Many people give up right here, days five to seven, exactly when nothing seems to be happening. Keep feeding it once or twice a day, keep it warm, and trust the process - a from-scratch culture usually takes one to two weeks, sometimes three, to rise predictably.

Not all flour feeds a starter equally. Bleached white flour is stripped of much of what the culture needs, and a starter on it can sputter. Whole grain - whole wheat or especially rye - is packed with the wild yeast, minerals and enzymes that drive fermentation. If your starter is sluggish, switch to feeding it at least partly whole-grain (try 50/50 rye and white) for a few feeds. Rye in particular can wake up a stalled starter dramatically. Also check your water: heavily chlorinated tap water can inhibit the culture, so let it sit out overnight or use filtered.

A thin grey or brown liquid pooling on top is hooch - alcohol the starter produces when it's hungry and has run out of food. It's a sign you're feeding too little or too infrequently, not a sign the starter is ruined. Either stir it back in for a slightly tangier result or pour it off, then feed straight away, and feed more often or at a higher ratio going forward. Once it's properly fed it'll rise again. More on this in the hooch explainer.

Two physical things can mask a perfectly active starter. First, consistency: a very wet, runny mix struggles to trap the gas the yeast produces, so it bubbles and froths but never builds a domed rise. Feeding a touch stiffer (slightly less water, closer to a thick paste than a batter) gives it the structure to actually climb. Second, the jar: in a wide, shallow container even a real doubling looks like almost nothing. Use a tall, straight-sided jar and mark the start level so a few centimetres of rise are easy to see.

Slow, flat or hooch-topped are all fixable and very common. The only things that genuinely mean trouble are mould (fuzzy spots in pink, orange, green or black) or a sharp, nail-polish-remover acetone smell that doesn't ease after a feed. Pleasant sour, yeasty or even faintly boozy smells are all fine. If you suspect the worst, our guide on troubleshooting a dead starter covers how to tell for sure and when to start over.