Read the mark before you move the jar
Set a band around the freshly fed level. Scrape the walls above that line before leaving the jar to rise. Later, look across the surface at eye level and check the walls just above it. Photographing the mark and the jar from the same angle makes the next morning's comparison easier.
| At this check | Likely stage | Useful next action |
|---|---|---|
| Higher than the previous reading and still climbing | Rising | Check again before the time you normally mix. |
| At the highest reading so far, with little change between checks | Near peak | Look at the recipe's readiness cues before using it. |
| Below the last recorded height or a fresh residue line | Falling | Record the last higher reading and the first lower one. |
| Old streaks, no baseline and a single reading | Peak unknown | Clean the walls above the line and try a monitored feed. |
A rounded surface can show the starter is still climbing. A flattening top can be useful alongside height, but flour and hydration can change how the surface looks. Compare the same jar across checks before drawing a conclusion from the shape of the top. [3] [2]
Did it peak overnight?
Here are two illustrative cases.
A clean jar tells a story. You feed at 20:30, mark 2 cm and clear the glass above the line. At 23:00 the starter is 3 cm and still climbing. At 07:00 it is at 4 cm, with a fresh band around 5 cm. That supports a rise followed by a fall. Record “peak between 23:00 and 07:00” and log the two observations. Avoid picking an exact time inside that interval.
Old streaks leave the time unknown. You feed at 20:30 and notice a line at 5 cm the next morning. The glass was already streaked after stirring, and you made no evening check. Log “peak unknown”. Use a clean-walled jar on the next feed or start earlier on a day when you can look twice.
A fresh residue line can estimate how high the starter rose. It cannot give you the hour. If you only saw the starter at feeding and after it fell, the possible window is wide. An extra check before bed can make the window much more useful.
What if two checks show the same height?
Note the interval and check once more if you can. Two readings at the same level may capture a short plateau. They may also miss a small rise and fall in between. A clean glass wall and a photo at each check help you see the difference. For planning a bake, a useful label is “near peak at both checks” rather than a timestamp you cannot support.
If you compare photos, keep the jar on the same flat surface, with the band and the top of the mixture visible. A photo looking down into the jar can show bubbles but makes it harder to judge height.
How do I move the peak closer to mixing time?
Once you have a few readings, compare feeds with the same ratio, flour and room temperature. A larger feed can move the window later. A warmer spot can move it earlier. Change one condition, record the result and leave enough room in the schedule if today's kitchen is different. [3]
Crispy Crust’s planned rise history is designed to keep that feed and its photos together. It would let you enter a peak window or leave it unknown, so your bake plan doesn’t depend on a time you never observed.
Can I use starter once it has started to fall?
If the starter has only just started to fall, consult the recipe’s instructions and compare it with your usual results. Some bakers use an active starter around peak, including shortly after it has begun to recede. A jar that has collapsed and been left for a long period is a less predictable starting point for a timed bake. Give it a fresh feed and use the recipe’s ripeness cues if you need a reliable window. [1] [2]
A peak describes this feed’s highest point. Before baking with a new starter, look for dependable activity across feeds and check that the culture meets the readiness criteria for your recipe. A single dramatic rise can be misleading during the first week. [4] [5]