Sourdough vs ordinary bread
Same four ingredients, different organisms — and the differences in flavour, keeping and texture all come from what the fermentation produced.
The short answer
A sourdough is raised by a maintained culture of wild yeasts and lactic acid bacteria; an ordinary loaf is raised by commercial yeast alone. The bacteria are the whole difference. They produce lactic and acetic acid, which lowers the pH and gives the characteristic sourness — and the acidity also changes gluten behaviour, slows staling and inhibits mould, which is why a sourdough keeps better without anything being added to it. The long fermentation a culture requires produces flavour compounds a fast yeasted dough never develops, so a sourdough tastes of more than wheat even when it is not noticeably sour. The chew people associate with sourdough is mostly hydration and fermentation length rather than the culture itself: a well-fermented high-hydration yeasted loaf has much the same texture. Wholemeal versus white is an entirely separate axis and can be combined with either — a wholemeal sourdough and a white sourdough differ in bran, not in fermentation.
Where they differ
| Dimension | First | Second |
|---|---|---|
| Leavening organisms | Wild yeasts and lactic acid bacteria, maintained as a culture. | Commercial yeast alone. |
| Fermentation time | Long — hours to overnight, often retarded cold. | Short, and controllable to the minute. |
| pH | Acidic. | Near neutral. |
| Flavour | Complex, and sour to a degree the baker controls. | Wheat and yeast. |
| Keeping | Longer — acidity slows staling and inhibits mould. | Shorter. |
| Effort | Requires maintaining a live culture. | A packet. |
Differences that do not matter
These are real distinctions that are unlikely to change your decision. They are listed so you can stop thinking about them rather than left out so the comparison looks decisive.
- Chew and crumb. Open and chewy, largely from hydration and fermentation length. Can be identical if fermented long and hydrated high.
Related
Compares
A subject of the comparison, so it is reachable from the record a reader is more likely to land on first.
A subject of the comparison, so it is reachable from the record a reader is more likely to land on first.