Master Crumb

Easy Sourdough Starter Recipe

Creating a sourdough starter from scratch is simple: mix flour and water, then feed it daily. In about a week, you'll have an active starter ready to leaven bread. Here's exactly how to do it.

What You Need

  • All-purpose or bread flour (whole wheat for first few days helps)
  • Water (room temperature, filtered if your tap water is heavily chlorinated)
  • A jar (quart/liter size works well)
  • A kitchen scale
  • A rubber band or marker

Day 1: Starting

Morning

In a clean jar, combine:

  • 50g whole wheat flour (or all-purpose)
  • 50g water

Mix thoroughly until no dry flour remains. The consistency should be like thick pancake batter.

Mark the level with a rubber band. Cover loosely (not airtight) and leave at room temperature.

What to Expect

Nothing yet. The wild yeast and bacteria haven't had time to multiply.

Day 2: Wait

Check your starter. You probably won't see much activity yet—that's normal.

Don't feed today. Just leave it alone. We're waiting for the wild yeast to establish.

Day 3: First Feeding

You might start seeing some bubbles. There may be a slightly fermented smell.

Discard and Feed

  1. Discard about half the starter (save for discard recipes or compost)
  2. Add 50g flour and 50g water
  3. Mix well
  4. Mark the new level

Cover and return to warm spot.

Day 4-5: Building Activity

Continue daily feedings:

  1. Discard half
  2. Add 50g flour + 50g water
  3. Mix and mark level

You should start seeing:

  • More bubbles
  • Rise and fall between feedings
  • Tangy, fermented smell (not unpleasant)

Day 6-7: Almost There

Your starter should be noticeably active now:

  • Doubles (or nearly doubles) within 4-8 hours of feeding
  • Lots of bubbles throughout
  • Pleasant yeasty/tangy aroma

Keep feeding daily. When it reliably doubles within 4-6 hours, it's ready to use.

The Float Test

To test if your starter is ready:

  1. Drop a small spoonful into a glass of water
  2. If it floats, it's active and ready
  3. If it sinks, it needs more time or a feeding

Troubleshooting

Nothing is Happening

Days 1-3 can be slow. If you see zero activity by day 5:

  • Move to a warmer spot (24-27°C / 75-80°F)
  • Try adding some whole wheat or rye flour
  • Make sure water isn't too chlorinated

It Smells Bad

Early on, some off smells are normal (acetone, cheese, etc.). Keep feeding—they usually resolve. If it smells rotten or has visible mold, start over.

Liquid on Top (Hooch)

This gray/brown liquid is alcohol. It means your starter is hungry. Stir it in or pour it off, then feed.

It Rose Then Fell Before I Could Feed

That's normal! Starter rises, peaks, then falls as food runs out. Try to feed at or just after peak.

After Day 7

Once your starter reliably doubles in 4-6 hours, you can:

  • Bake with it: Use at peak activity
  • Feed daily: If keeping at room temperature
  • Refrigerate: Feed once a week if not baking often

Ongoing Maintenance

Room Temperature

Feed daily (or twice daily in warm weather). Use or discard before each feeding.

Refrigerated

Feed at least once a week. Take out night before baking, feed, let reach peak, then use.

Naming Your Starter

Many bakers name their starters. It sounds silly, but it helps you think of it as a living thing that needs care. Popular names: "Clint Yeastwood," "Doughvid Bowie," "Bread Pitt."

Success Signs

You'll know your starter is healthy when it:

  • Doubles within 4-6 hours of feeding
  • Has a pleasant, tangy smell
  • Is full of bubbles throughout
  • Has a domed top at peak
  • Passes the float test

Congratulations—you've created a living culture that can last for years (or decades!) with proper care.