This is the reference entry the rest of the ledger points back to. The 1:5:5 refresh — 20 g starter, 100 g flour, 100 g water at 24 °C — is not the only way to keep a starter, but it is the one with the widest usable window, and most baking failures I have written down start with a starter that was used at the wrong hour.
What each hour actually looks like
A starter fed 1:5:5 at 24 °C with a 60/40 bread-flour-to-whole-wheat blend has a predictable shape over eleven hours. The rise is not the useful signal on its own — the smell and the texture of the top surface tell you more, and they change before the height does.
| Hour | Height | Smell | Surface | Use it? |
|---|---|---|---|---|
| 0 | Baseline mark | Yoghurt, faint acetone | Pasty | No |
| 3 | +40% | Fresh dough, no acid | Matte, small bubbles | No |
| 5 | +120% | Sweet, yeasty | Glossy, domed | Early but rising fast |
| 7-9 | +200%, peak | Ripe, lightly sour | Dome, 1-3 holes on top | Yes — this is the window |
| 11 | Falling | Sharp, vinegar | Collapsed centre | Only for discard recipes |
Why 1:5:5 beats 1:2:2 for a home baker
At 1:2:2 the starter peaks in about three hours, which is fine if you are baking on a schedule you can watch. At 1:5:5 it peaks in seven to nine, which means you can feed it before bed and mix dough in the morning, or feed it in the morning and mix after work. The trade is that you need a bigger jar, and that a 1:5:5 starter left at 28 °C in summer will still run out of food in five hours.
Temperature moves the whole table
Every 4 °C above 24 °C cuts about 1.5 hours off the peak. At 20 °C the peak arrives at hour eleven; at 28 °C it arrives at hour five. Rather than memorising windows, use the table above and shift it: if your kitchen is at 20 °C, read "hour 7-9" as "hour 11-13".
- Keep at least 200 g of starter in the jar so a 1:5:5 feed stays proportional.
- A starter that separates with dark liquid on top is hungry, not dead; pour the liquid off and feed 1:3:3 twice.
- Rye starter at 1:5:5 peaks faster and sours harder; use a 1:6:6 for rye.
A starter that smells of acetone is not ruined, but it will not leaven a loaf on that schedule. Feed it, wait for the dome, and use it — never mix a dough with a starter that is already falling.