A starter can be active at breakfast and sluggish by dinner. That does not automatically mean it is weak. It means temperature, feeding ratio, flour and microbial activity have changed the fermentation curve. The useful skill is learning to read that curve.

1. Track the rise, not just the hours

Mark the starter level immediately after feeding. Watch how far it rises, how long it holds, and when it begins to fall. A starter used near its peak often behaves differently from one that has already collapsed. Neither one can be judged reliably by an arbitrary number of hours.

2. Observe the surface and structure

An active starter often shows a domed or gently rounded surface, visible gas bubbles and a lighter structure. At or after its peak, the surface may flatten or recede. Different flours and hydration levels can change these signs, so assess several cues together rather than looking for one perfect bubble pattern.

3. Smell for change

A healthy, regularly maintained starter can smell mildly fruity, lactic or pleasantly acidic. Aroma varies with feeding pattern and temperature. Strong, harsh acidity can suggest that the culture has spent longer without feeding, but smell alone does not establish how it will perform in dough.

4. Control one variable at a time

If your starter seems unpredictable, standardise the container, flour, hydration and feeding ratio before changing everything at once. Record the room temperature and time to peak. A short note after each refresh is more useful than guessing.

5. Make a simple test

• Feed at a consistent ratio and mark the starting level.
• Record the temperature and the time taken to rise and begin falling.
• Use the starter at a repeatable stage of maturity.
• Compare loaf fermentation and oven performance across several bakes.

What about the float test?

Floating is not a definitive measure of readiness. Trapped gas and the way a sample is handled can affect the result. Track repeatable activity and how the culture performs in actual dough instead.

The objective is not to own a starter that follows a timetable. It is to understand a living culture well enough to use it consistently.

This is the kind of foundational observation that scales from one loaf at home to a small production schedule.