The Ultimate Guide to Sourdough Baking

What is a Sourdough Starter and How Does it Make Bread Rise?

A sourdough starter is a live culture made from flour and water, containing wild yeast and beneficial bacteria. These microorganisms ferment the mixture, producing carbon dioxide gas that makes bread rise and lactic acid that creates the tangy sourdough flavour. Unlike commercial yeast, the starter offers a natural, slower fermentation process, resulting in unique textures and tastes.

The slow fermentation allows for the breakdown of complex starches and proteins in the flour, making sourdough bread easier to digest. The natural acids also act as preservatives, giving sourdough bread a longer shelf life without the need for additives. This traditional process has been used for thousands of years and continues to be a favourite among artisan bakers and home enthusiasts alike.

How Do Different Flours Affect the Starter?

The type of flour you use greatly influences your starter’s activity and flavour:

All-Purpose Flour: Reliable and versatile, it provides a consistent food source for your starter but may lack the nutrients found in whole grains.

Whole Wheat Flour: Packed with nutrients, it boosts fermentation activity and creates a nutty flavour.

Rye Flour: Encourages vigorous fermentation due to its high nutrient and enzyme content. It’s an excellent choice for boosting a sluggish starter.

Spelt Flour: Spelt has a mild, sweet flavour and a softer gluten structure. It can enhance fermentation while adding subtle complexity to the starter.

Organic Flour: Minimizes exposure to chemicals and additives that could hinder microbial activity.

Combining different flours can help you create a balanced starter. For example, using rye flour for initial feedings can speed up the fermentation process, while transitioning to all-purpose flour provides a more neutral base for baking a variety of breads. Experimenting with flour blends allows you to tailor the flavour profile of your sourdough to your liking.

Why and How Do You Feed It?

Feeding your starter replenishes its food supply, keeping the yeast and bacteria active and healthy. Here’s how to do it:

Measure: Use a 1:1:1 ratio by weight (starter, flour, and water).

Mix: Combine the ingredients in a clean jar, stirring until smooth.

Cover: Use a breathable lid or cloth to allow air exchange while protecting against contamination.

Store: Leave the starter at room temperature until bubbly, or refrigerate if not baking frequently.

Regular feedings maintain your starter’s strength and ensure consistent results. Over time, you’ll learn to adjust feeding schedules based on your starter’s activity and your baking frequency. A well-fed starter smells pleasantly tangy, has a thick but pourable consistency, and produces plenty of bubbles.

How Can It Be Stored?

Your sourdough starter can be stored based on your baking frequency:

Room Temperature: For daily bakers, feed your starter every 12-24 hours.

Refrigeration: Ideal for occasional bakers. Feed it weekly to keep it alive and active. Always let it return to room temperature and feed it before baking.

For long-term storage, you can also dry your starter by spreading it thinly on parchment paper and letting it air-dry completely. Once dry, break it into flakes and store it in an airtight container. To reactivate, mix the flakes with equal parts water and flour and follow your normal feeding routine until the starter becomes active again.

Proper storage ensures your starter stays ready to use while minimizing waste. Always store it in a clean, odour-free container to avoid contamination.

Why Should You Discard Some of the Starter When You Feed It?

Discarding part of your starter prevents it from growing too large and becoming unmanageable. It also maintains the right balance of yeast and bacteria by providing fresh food. Without discarding, your starter may become too acidic and less effective at fermenting dough.

Discard doesn’t have to go to waste! Use it in creative ways:

Pancakes or Waffles: Add discard to your batter for extra flavour.

Crackers: Mix with flour, spices, and oil to create crunchy sourdough crackers.

Pizza Dough: Incorporate discard into your pizza dough recipe for a tangy kick.

By finding ways to use discard, you can enjoy the benefits of sourdough in more than just bread.

How to Tell It’s Ready to Use

A starter is ready to bake when:

It doubles in size within 4-6 hours after feeding.

The surface is bubbly, and the aroma is pleasantly tangy.

It passes the float test: a spoonful of starter floats in water.

To ensure consistency, monitor your starter’s behaviour over time. Keeping a feeding log can help you identify patterns and make adjustments. A ready starter will also have a slightly domed top, indicating peak activity.

What to Do If My Starter Isn’t Looking Healthy

If your starter appears sluggish, smells off, or has discolouration, take these steps:

Remove Contaminated Parts: If mold or dark spots appear, discard the affected portion.

Refresh: Feed smaller portions (e.g., 20g starter, 40g flour, 40g water) twice daily.

Switch Flour: Use whole wheat or rye flour temporarily to boost activity.

Warm It Up: Keep the starter in a warm area (21-25°C/70-77°F) to encourage fermentation.

Be Patient: It may take several days of consistent feeding to restore full activity.

A healthy starter should smell tangy but not unpleasant. If it smells like alcohol or acetone, it’s a sign that it needs more frequent feedings. If you’re unsure, a small test bake can help confirm its health.

This guide offers everything you need to master sourdough, from maintaining a starter to baking exceptional bread. Enjoy the journey and happy baking!