How to Make a Sourdough Starter from Scratch by Eyeball Feeding

This video walks through building a sourdough starter from day one to fully active in a single tutorial. The key philosophy: no measuring. You learn to eyeball every feeding based on consistency, which makes the starter sustainable long-term. If you have to weigh flour and transfer to a new jar every day, you will give up. This method is built for people who want to actually keep their starter alive.

Day One: Starting From Nothing

Creator at her kitchen counter with an empty Weck jar, introducing the sourdough starter process

Start with any jar that can hold a loose-fitting lid. Weck jars work, mason jars work, any container with a non-airtight cover works. A paper towel with a rubber band is fine too. The lid just needs to sit on top without sealing.

Use unbleached all-purpose flour or unbleached bread flour. Add a couple spoonfuls to the jar, then add room-temperature water a little at a time. Stir until you reach a thick consistency. The test: flip the jar upside down for two to three seconds. If nothing falls out, you are at the right thickness. Set the lid on (not sealed) and leave it on the counter.

Days Two Through Four: Feeding and Watching

Feed the starter the same way every day: a couple spoonfuls of flour, water added gradually until you hit that same thick consistency. On days two and three, there is no visible growth. That is normal. Do not discard anything yet because there is plenty of room in the jar.

Creator holding the jar on day three or four, showing early bubbles forming in the starter

By day three or four, you will start seeing bubbles. The starter is not doubling yet, but there is activity. Once the jar gets close to halfway full, start discarding before feeding. Discard is just starter you throw away to make room. There is no chemical difference between "discard" and "starter." It is the same substance.

The rule: after feeding, the starter should sit below the halfway mark of your jar. That leaves room for it to double without overflowing.

Day Five: Signs of Life

By day five, the starter is showing real activity. Bubbles are everywhere. The creator notes this is probably the fastest she has ever had a starter become active. By late on day five, it has risen significantly, possibly near doubling.

Creator on day five holding the jar up to show the starter has risen and is full of bubbles

Day Six: Fully Active

By day six, the starter has clearly doubled. It is fully active and ready to bake with. To confirm, the creator feeds it and watches it double again within five to six hours.

Creator proudly holding up the fully active, doubled sourdough starter on day six

From this point, maintenance is the same process: discard to below half, feed with a couple spoonfuls of flour and water to the same thick consistency, leave on the counter. That is it.

Variables That Affect Speed

Your starter might take longer than six days. Several factors influence the timeline:

House temperature (warmer speeds it up)
Water temperature
Water source (filtered, tap, etc.)
Flour brand and type

Do not worry if yours takes eight or ten days. The process is the same regardless of speed.

Key Takeaways

Eyeball feeding by consistency (thick enough to flip upside down for three seconds) is more sustainable than measuring
Discard is just starter you remove to make room in the jar; it is not a separate substance
Keep the starter below the halfway mark after feeding so it has room to double
A starter can become fully active in as few as five to six days, though your timeline may vary
Once active, maintain it with the same daily feeding routine