A sourdough starter is just flour and water that you have cultivated wild yeast and bacteria into. That is it. The process that appears intimidating is actually forgiving: you cannot fail if you feed it regularly and give it time. Most starter failures come from impatience, not error.
Sourdough bread is leavened by wild yeast naturally present in flour and the environment. Unlike commercial yeast, which produces a predictable rise in a predictable time, sourdough fermentation is slower, more variable, and produces the complex flavour and open crumb that commercial yeast cannot replicate. The process takes days to establish and minutes of active work each day. The result is worth both.
What You Need
- Strong flour (bread flour with 12 to 14 percent protein. Plain/all-purpose flour works but is slower)
- Water (room temperature tap water. If heavily chlorinated, let it stand for 30 minutes or use filtered)
- A clean jar (at least 750ml capacity)
- A digital scale (essential: measuring by weight, not volume, is non-negotiable for consistent results)
- A rubber band or marker to track starter rise
Day-by-Day Starter Creation
Day 1: The Beginning
Combine 50g wholemeal or whole-wheat flour with 50g room-temperature water in a clean jar. Stir thoroughly to combine and ensure no dry flour remains. Cover loosely (the lid should not be sealed airtight as fermentation produces CO2 gas). Leave at room temperature, ideally 21 to 24 degrees Celsius. Nothing will happen today. This is normal.
Day 2: First Feed
You may see small bubbles. You may not. Either is fine at Day 2. Discard all but 50g of your starter. This discard step feels wasteful but prevents the starter from accumulating too much acidity relative to the available food. Add 50g fresh flour and 50g water. Stir well. Cover loosely.
Day 3 to 4: Signs of Life
By Day 3 or 4, you should see consistent bubbling and the starter should begin to rise and fall. It may smell strongly acidic or even unpleasant at this stage. This is normal early-stage fermentation where bacteria are establishing before the yeast population becomes dominant. Continue discarding and feeding with 50g flour and 50g water every 24 hours.
Day 5 to 7: The Starter Matures
Your starter is ready to use when it reliably doubles in size within 4 to 8 hours of feeding and has a pleasant sour-yeasty smell rather than a harsh acidic one. The float test provides additional confirmation: drop a teaspoon of starter into a glass of water. If it floats, there is sufficient gas production for leavening. If it sinks, give it another day.
The most common reason starters fail to develop: Temperature too low. Wild yeast is much slower below 18 degrees Celsius. If your kitchen is cool, place the jar in the oven with just the oven light on (creates approximately 27 degrees) or find a warm spot near a radiator.
How to Maintain Your Starter
Once established, you can keep your starter at room temperature (requires daily feeding) or in the refrigerator (requires weekly feeding). Refrigerator storage is more practical for most bakers who do not bake every day.
Refrigerator maintenance: Once per week, remove from fridge, discard down to 50g, feed with 50g flour and 50g water, leave at room temperature for 4 to 6 hours until active, then return to the fridge. Before baking, remove from fridge the night before and feed to activate.
The discard: The flour and water you remove each feeding has many uses: sourdough pancakes, crackers, pizza dough, and sourdough banana bread. Never throw it away once your starter is established.
Your First Sourdough Loaf
This is a simple beginner loaf. The dough requires no kneading: only stretch and folds and time.
Ingredients (1 loaf): 450g strong white bread flour, 325ml room-temperature water, 100g active starter (fed 4 to 8 hours ago and at peak activity), 10g salt.
- Mix flour and 300ml water. Rest 30 minutes (autolyse: develops gluten structure without kneading).
- Add starter and salt. Mix thoroughly by squeezing through fingers. Add remaining 25ml water gradually.
- Stretch and fold: every 30 minutes for the next 2 hours, grab one side of the dough and fold it over to the opposite side. Rotate the bowl 90 degrees and repeat 4 times. Rest between sets.
- After the bulk ferment (typically 4 to 8 hours at room temperature until the dough is puffy and has small bubbles on the surface), gently shape the dough into a tight round.
- Place seam-side up in a floured proving basket (banneton) or a bowl lined with a floured cloth. Cover and refrigerate overnight (8 to 16 hours).
- Preheat oven with a Dutch oven inside to 250C (480F) for 1 hour minimum. Cold dough directly from the fridge goes into the hot Dutch oven. Score the top with a sharp knife or blade. Bake covered 20 minutes, then uncovered 20 to 25 minutes until deep golden brown.
- Cool completely on a wire rack before cutting. Minimum 1 hour. The interior is still cooking during this time.
| Why Cold Proofing Overnight Works
Refrigerating the shaped dough overnight does two things: it develops deeper flavour through slow fermentation, and it makes the dough firm and easy to score cleanly before baking. The cold also slows fermentation, giving you flexibility on baking time. You can leave it in the fridge for up to 24 hours. |
How long does it take to make a sourdough starter from scratch?
A sourdough starter typically takes 5 to 7 days to become reliably active. The starter is ready when it doubles in size within 4 to 8 hours of feeding and passes the float test. Cooler temperatures slow the process. Most first-time starters take the full 7 days rather than 5.
Why does my sourdough starter smell bad?
Strong acidic or even unpleasant odours in the first 2 to 4 days are normal. Bacteria dominate early fermentation before the yeast population is established. By Day 5, the smell should develop into a pleasant sour-yeasty quality. If the smell is alcoholic and the starter looks liquid and grey on top, it is very hungry: discard and feed immediately.
What does it mean to discard sourdough starter?
Before feeding, you remove most of the starter (leaving 20 to 50g) and add fresh flour and water. This prevents the starter from becoming too large to manage and keeps the pH balanced so the yeast can thrive. The discarded portion is not wasted: it can be used in sourdough pancakes, crackers, or other recipes.
Why do you use a Dutch oven for sourdough baking?
A Dutch oven traps steam released by the dough in the first 20 minutes of baking. This steam keeps the crust soft and pliable during oven spring (the rapid rise when dough hits oven heat), allowing maximum expansion. After 20 minutes, removing the lid allows the crust to brown and crisp. Without a Dutch oven, the crust sets too quickly and the loaf cannot expand fully.
How do you know when sourdough starter is ready to use?
Two indicators: the starter doubles in volume within 4 to 8 hours of feeding, and it passes the float test (a teaspoon dropped in water floats rather than sinks). Use the starter at peak activity, when it has risen to maximum height and not yet begun to deflate. Using it too early or too late reduces the leavening power.
Can you keep a sourdough starter in the fridge?
Yes. Refrigerator storage requires only weekly feeding rather than daily. Remove once per week, discard to 50g, feed with 50g flour and 50g water, leave at room temperature for 4 to 6 hours until active, then return to the fridge. Before baking, remove the night before and feed to activate at room temperature.
Time Is the Main Ingredient
The skill in sourdough is not the technique. It is the observation: learning to read your starter, knowing what peak activity looks and smells like, recognising when your dough is ready to shape. None of this takes more than 10 minutes of active attention per day. All of it comes from simply doing it repeatedly and noticing what changes.