How to Make a Sourdough Starter from Scratch
Slug: how-to-make-sourdough-starter-from-scratchPillar: Food and Drink > Cooking TipsKeyword: how to make sourdough starter from scratchExcerpt: Learn how to make a sourdough starter from scratch in 7 days using just flour and water — with a day-by-day feeding guide and troubleshooting tips.
What Is a Sourdough Starter?
A sourdough starter is a live culture of wild yeast and beneficial bacteria that naturally exists on flour and in the air. It's what makes sourdough bread rise and gives it that distinctive tangy flavour. Unlike commercial yeast, a starter is self-sustaining: feed it flour and water regularly, and it will last indefinitely — some famous bakery starters have been kept alive for over a century.
What You'll Need
Wholemeal or strong white bread flour, filtered or tap water left overnight to off-gas chlorine, a glass jar or non-reactive container (at least 1 litre capacity), kitchen scales (measuring by weight is far more reliable than by volume), and a rubber band to mark the starter's rise level.
The 7-Day Day-by-Day Guide
Day 1: Combine 50g wholemeal flour and 50g water at room temperature in your jar. Mix thoroughly, cover loosely, and leave for 24 hours. Day 2: Discard half the mixture (50g), then add 50g flour and 50g water. Mix well, cover, and leave for another 24 hours. Days 3–5: You may see a "false rise" from leuconostoc bacteria — this is normal and will pass. Continue discarding half and feeding daily. Day 6: You should start seeing a genuine rise after feeding with a pleasant, yeasty or yoghurt-like smell. Day 7: Do the float test — drop a small spoonful into water. If it floats, it's ready. If it sinks, continue for 2–3 more days.
How to Feed Your Starter Long-Term
At room temperature: feed daily (discard 80%, feed equal parts flour and water by weight). In the fridge: feed once a week. Refrigerated starters go dormant between feedings. To bake: remove from the fridge the evening before, feed it, leave at room temperature overnight.
Troubleshooting Common Problems
If not bubbling after 5 days: move to a warmer location — even moving from 18°C to 24°C makes a significant difference. Pink or orange streaks indicate contamination — discard and start over. Grey liquid on top (hooch) means the starter is hungry — stir it back in or pour it off, then feed.
FAQ
Can I use plain all-purpose flour for a sourdough starter?
Yes, but wholemeal flour produces faster, more active starters. Starting with wholemeal and switching to white bread flour after a week is the most reliable approach.
Why do I need to discard half the starter?
Without discarding, the ratio of food to organisms becomes unfavourable and the pH drops too low for yeast to survive. Discard also prevents your starter from becoming unmanageably large.
Can I use the discarded starter for anything?
Yes — sourdough discard is excellent in pancakes, waffles, crackers, banana bread, and pizza dough.
How long does a sourdough starter last?
Indefinitely, if fed regularly. Refrigerated starters can be neglected for a week or two and revived with a few days of daily feeding at room temperature.
What's the best flour for sourdough starter?
Strong white bread flour for long-term feeding. Avoid self-raising flour — the added baking powder interferes with fermentation.
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