A bubbly, doubled sourdough starter in a glass jar with a rubber band marking its starting level.

Baking Basics - Build from flour + water

Sourdough Starter

A straightforward flour-and-water culture built day by day, with a clear schedule for feeding, storing, and waking it for baking.

Total time
7 days or longer
Hands-on
About 5 min daily
Yield
1 starter
Starter
Build from flour + water
Difficulty
Beginner
Environment
Room temperature; refrigerate once ready
Pan or vessel
Glass jar with a loose lid

Gather first

Ingredients

Before You Begin

Ingredients

  • Bread flour
  • Bottled or filtered water

Build Your Starter

Day 1 — Begin

  • 1/2 cup (125 ml) bread flour
  • 1/2 cup (125 ml) bottled or filtered water

Day 2 — Feed

  • 1/3 cup (80 ml) bread flour
  • 1/3 cup (80 ml) bottled or filtered water

Day 3 — Feed Again

  • 1/3 cup (80 ml) bread flour
  • 1/3 cup (80 ml) bottled or filtered water

Day 4 — Discard & Feed

  • Half of the starter
  • 1/3 cup (80 ml) bread flour
  • 1/3 cup (80 ml) bottled or filtered water

Day 5 — Feed

  • 1/3 cup (80 ml) bread flour
  • 1/3 cup (80 ml) bottled or filtered water

Day 6 — Discard & Feed

  • Half of the starter
  • 1/3 cup (80 ml) bread flour
  • 1/3 cup (80 ml) bottled or filtered water

Day 8 — Continue if Needed

  • 1/3 cup (80 ml) bread flour
  • 1/3 cup (80 ml) bottled or filtered water

Method

Step by step

Part 1

Build Your Starter

Room-temperature schedule
  1. Day 1 — Begin — Mix together, place the lid on top without sealing it, and leave on the counter for 24 hours.
  2. Day 2 — Feed — Add to the starter, mix well, cover without sealing, and rest on the counter for 24 hours.
  3. Day 3 — Feed Again — Add to the starter, mix well, cover without sealing, and rest on the counter for 24 hours.
  4. Day 4 — Discard & Feed — Discard half, add the flour and water, and mix. Cover without sealing and leave on the counter for 24 hours.
  5. Day 5 — Feed — Add to the starter, mix well, cover without sealing, and rest on the counter for 24 hours.
  6. Day 6 — Discard & Feed — Discard half, add the flour and water, and mix. Cover without sealing and leave on the counter for 24 hours.
  7. Day 7 — Check for Readiness — If the starter has doubled in size, it is ready to use. If it has not doubled, discard half; add 1/3 cup (80 ml) bread flour and 1/3 cup (80 ml) bottled or filtered water; mix; cover without sealing; and rest for another 24 hours.
  8. Day 8 — Continue if Needed — Mix, cover without sealing, and leave on the counter for 24 hours.

Part 2

Store & Wake the Starter

Between bakes
  1. Once the starter is ready, close the lid and refrigerate it when you are not baking.
  2. To reactivate, add 1/4 cup water and 1/3 cup bread flour.
  3. Mix, cover without sealing, and leave on the counter for 3-5 hours, or until doubled.
    Set a check timer
    Choose when to check; the step's visual cues decide when it is ready.
  4. A gray or black liquid may collect on top in the refrigerator. Pour it off or mix it back in.
  5. Add 1/4 cup water and 1/3 cup bread flour, then mix well.
  6. Leave on the counter for 3-5 hours, or until doubled and ready to use.
    Set a check timer
    Choose when to check; the step's visual cues decide when it is ready.

Part 3

Helpful Notes

For next time

My Kitchen Notes

Keep track of changes, room temperature, proofing cues, or anything you want to repeat next time.

Private to this device.

Finish well

After the build

Readiness, storage, and reactivation notes for your starter.

Ready when

Ready when it reliably doubles in size

Storage

Close the jar and refrigerate the starter when you are not baking.

Reactivate

Feed with 1/4 cup water and 1/3 cup bread flour, then leave at room temperature for 3–5 hours or until doubled.