How to Make a Sourdough Starter: A Beginner’s Guide

February 3, 2026

What Is a Sourdough Starter?

A sourdough starter is a live culture of wild yeast and lactic acid bacteria that naturally ferments flour and water. Unlike commercial yeast, a starter leavens bread slowly, giving sourdough its distinct tangy flavour, chewy texture, and long shelf life.

Making your own starter is simple, inexpensive, and incredibly rewarding. No special ingredients are needed, just flour, water, and patience.

Ingredients You’ll Need

50 g (¼ cup) whole wheat or rye flour (whole grain flours have more natural wild yeast)
50 g (¼ cup) lukewarm water
A clean glass jar or container (500 mL / 2 cup size is ideal)
A spoon or small spatula for stirring

Use filtered or bottled water if your tap water is heavily chlorinated, as chlorine can inhibit fermentation.

Step 1: Mix Your First Batch

1. Add 50 g of flour and 50 g of water to your jar.
2. Stir until there are no dry patches, forming a thick, paste-like batter.
3. Scrape down the sides and cover loosely with a lid, cloth, or plastic wrap.

Don’t seal the jar tightly as the starter needs air for wild yeast to grow.

Step 2: Let It Rest

Keep the jar at room temperature (20–25°C / 68–77°F).
Let it sit 24 hours.

You may not see much activity yet. This is normal. Patience is key.

Step 3: Feed Your Starter Daily

For the next 5–7 days, you’ll feed your starter once every 24 hours:

1. Discard about half of the starter (50 g). This keeps it manageable and encourages yeast growth.
2. Add 50 g flour and 50 g water. Stir well.
3. Cover loosely and leave at room temperature.

Within a few days, you should notice bubbles, a mild tangy smell, and some rise after feeding.

Step 4: Observe and Adjust

Bubbles mean your yeast is active.
Tangy or slightly sweet smell is normal.
If your starter develops pink, gray, or black mold, discard and start over.

Helpful Hint: Rye or whole wheat flour starters tend to be faster and more vigorous.

Step 5: Determine When Your Starter Is Ready

Your starter is ready to bake with when:

It doubles in size within 4 - 6 hours of feeding.
It is bubbly and airy.
It floats in water.

Once ready, you can use it to bake sourdough bread, pancakes, waffles, or pizza dough.

Step 6: Maintaining Your Starter

Daily feeding at room temperature: if baking frequently.
Refrigerated starter: feed once a week, store in the fridge, and bring back to room temperature before baking.
Always discard or use half before feeding to keep the culture healthy.

Tips for Success

Use consistent measurements. Weighing flour and water is more reliable than cups.
Keep it warm. Warmth encourages fermentation; too cold slows it down.
Be patient. Starters can take 5 - 7 days or more to become fully active.
Avoid metal bowls or utensils: glass, plastic, or wood is best.

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