Make Your Own Starter in 7 Days
A day-by-day guide to growing a sourdough starter from just flour and water. It's a fun, fascinating week that teaches you the most important lesson in sourdough — time.
You can get starter from a bakery or a neighbour, but I recommend making your own at least once. It teaches you the most important thing about sourdough: the importance of time.
You need: a clean glass jar, a kitchen scale, wholegrain flour (rye or wheat), white flour, and filtered water.
Day by day
| Day | What to do | What you’ll see |
|---|---|---|
| 1 | Mix 50 g wholegrain flour + 50 g water. Cover loosely. | Nothing yet — that’s normal. |
| 2 | Leave it alone. | Maybe a few bubbles. |
| 3 | Keep 50 g, discard the rest. Feed 25 g wholegrain + 25 g white + 50 g water. | Often a sudden burst of activity. Don’t be fooled! |
| 4 | Same feeding, once a day. | Activity may drop. Keep going — this is the bacteria settling down. |
| 5–6 | Feed twice a day, 1:1:1, gradually switching to your everyday flour mix. | Rising more predictably, smelling tangy. |
| 7+ | Feed 1:1:1 twice a day. | Doubles within 4–8 hours of each feeding: it’s ready. |
Tips that make the difference
- Warmth matters most. 24–27°C is ideal. The top of the fridge or an oven with just the light on works well.
- Wholegrain first. It carries more wild yeasts and bacteria than white flour.
- The day-3 bubbles lie. An early surge is from bacteria that fade away. The real, stable activity comes later.
- Be patient. In a cool kitchen it can take 10–14 days. That’s fine.
Once it reliably doubles, move on to the starter maintenance guide and bake your first Master Loaf.
Want the whole method in one place?
Get the free Master Loaf guide: recipe, timelines, starter checks and a crumb diagnosis chart.
