Troubleshooting a Sourdough Loaf That Looks Dense

Start by Reading the Crumb

Before you change a single thing in your recipe, cut the loaf in half and look properly at what you have made. A dense crumb has several distinct signatures, and each one points to a different culprit. Dense and slightly gummy at the base with a few large, irregular holes tunnelling up under the top crust is the classic mark of an underproved loaf. An even, tight, uniform crumb right through the middle, combined with a pale crust and a loaf that spread rather than rose, usually means the dough was left too long and the structure collapsed. A sticky, gummy line just above the bottom crust is more often an underbaked loaf or one sliced while still hot than a proving problem at all. And a single large cavern just beneath the top crust is nearly always trapped air from shaping, not fermentation.

Get into the habit of photographing your cut loaf alongside a note of the timings. Three or four bakes recorded this way will tell you more than any amount of guesswork.

Is Your Starter Genuinely Ready?

Most dense loaves trace back to a starter that is technically alive but too weak to lift a full batch of dough. A starter at 100% hydration, fed at roughly 1:5:5 by weight (starter, flour, water) and kept at 24–26°C should double or more within four to six hours. It should smell yeasty with a clean sour note, form a domed top, and be at its highest point when you use it.

Two common mistakes. The first is trusting the float test. A starter can float on water and still be far too weak to raise a loaf, because the float only tells you it holds some gas, not that it has the strength to keep producing it for eight hours. The second is using a starter past its peak, once it has collapsed and smells sharply of acetone. That starter has already spent its energy.

• If your starter takes twelve hours to double, it needs more frequent feeding, a warmer spot, or both.
• Feed it twice a day for three or four days before a bake, discarding down properly each time.
• Swap in 20–30% wholemeal or rye flour for a few feeds; the extra minerals and enzymes wake a sluggish culture quickly.
• Use it when it has risen to its peak, not when it has fallen back.

Proving: the Two Ways a Loaf Goes Wrong

Underproving and overproving both produce a close crumb, which is why bakers so often adjust the wrong direction. Keep your dough between 24°C and 26°C and watch the dough, not the clock. For a standard 500g-flour loaf, aim for a bulk rise of 50–75% in volume, not a full doubling. A small aliquot jar filled with a spoonful of the same dough and marked with an elastic band will tell you exactly when that has happened.

Then use the poke test. Flour your finger and press gently into the dough. If the dent springs back quickly and completely, it is underproved. If it springs back slowly and leaves a partial indent, it is ready. If it stays put and the dough feels slack and lifeless, it has gone too far.

If you cold-retard, keep the fridge at 4–5°C for 12–16 hours. A warmer fridge will push the dough on far faster than you expect, and a loaf retarded for twenty hours in a 7°C fridge will be flat and dense by morning.

Shaping Tension Does More Than You Think

A slack, loosely shaped loaf spreads sideways in the oven, and the gas you worked so hard to build escapes without lifting the crumb. Tension is what holds the shape.

After bulk fermentation, pre-shape lightly, then leave the dough uncovered on the bench for 20–30 minutes. This rest relaxes the gluten so the final shape can be tightened without tearing. When you shape, use the heel of your hand and the bench scraper to drag the dough towards you, building a taut skin on top. Use as little flour as you can get away with; too much dusting stops the dough gripping the bench, which is exactly where the tension comes from. A good final shape feels like a tight drum, and the seam holds shut on its own.

Hydration, Flour and the Bake Itself

An open crumb needs strong flour and enough water, but too much water for the flour you have will give you a flat, dense loaf every time. If you are using a standard strong white bread flour, start at 70–75% hydration and only increase once you are consistently getting good rise. Wholemeal and rye absorb more water but also ferment faster, so adjust timings as well as liquid.

• Add salt at around 2% of the flour weight; skip it and the gluten will be weak and the crumb tight.
• Give the dough a 30–60 minute autolyse before mixing for a more extensible, easier-to-shape dough.
• Bake in a preheated Dutch oven at 240°C for 20 minutes with the lid on, then 20–25 minutes at 220°C with the lid off.
• Check the internal temperature: 96–98°C means it is done.
• Cool on a wire rack for at least two to three hours. The crumb sets as it cools, and cutting early gives you the gumminess you were trying to fix.

A Repeatable Plan for Your Next Loaf

Change one variable at a time. Build a strong starter and use it at peak. Ferment at a steady, measured temperature and stop the bulk at 50–75% rise. Shape with real tension and prove until the poke test gives you a slow, partial spring. Bake hot, with steam, and wait before you cut.

Keep notes on temperature, timings and the look of the crumb, and within a handful of bakes you will have a loaf that opens up reliably rather than by luck.