Sourdough bread: from your first starter to a crackling crust
How to grow a starter from flour and water in a week and how to feed it, a base 70% hydration loaf, stretch-and-folds instead of kneading, how to tell the dough has risen, cold proofing and baking in a cast-iron pot. Step by step, with grams and times.
What a starter is
A starter is a living culture of wild yeast and lactic acid bacteria that live in flour and in the air. The yeast raises the dough; the bacteria give the bread its characteristic tang, deep aroma and longer keeping. Sourdough stays fresh for 3–4 days and resists mould longer.
All you need for a starter is flour, water, a jar and a week of patience. Grown once and looked after, a starter lives for years.
Growing a starter in 5–7 days
It's best to begin with wholegrain rye flour: it carries more wild yeast and nutrients, so the starter wakes up faster. You can switch it to wheat later. Use filtered or rested water: chlorine in tap water inhibits the microbes.
- Day 1: mix 50 g flour and 50 g warm water (25–28 °C) in a jar. Cover loosely and leave at room temperature.
- Day 2: the first bubbles may appear. Add 50 g flour and 50 g water and stir.
- Days 3–7: each day, discard all but 50 g of starter and feed it 50 g flour and 50 g water.
- On day 2–3 the starter may rise vigorously and then go quiet — that's normal: other bacteria multiply first, then the right ones take over. Keep feeding.
- The starter is ready when it reliably doubles within 4–8 hours of feeding, smells pleasantly sour like yoghurt or apple, and is full of bubbles.
Looking after a starter
If you bake often, keep the starter at room temperature and feed it once a day. If you bake once a week, keep it in the fridge and feed it every 5–7 days.
The standard 1:1:1 feed is 1 part starter, 1 part flour, 1 part water by weight — for example 50 g starter + 50 g flour + 50 g water. For slower, more sour development, use 1:2:2 or 1:5:5.
8–12 hours before baking, take the starter out of the fridge and feed it. Use it at peak activity — when it has risen as high as it will go but hasn't started to fall.
The base loaf: ratios
This recipe makes one loaf of about 850 g — bread with an open, holey crumb and a crisp crust.
- 450 g strong white bread flour (12–13% protein)
- 50 g wholemeal wheat or rye flour
- 350 g water (70% hydration)
- 100 g active starter (20%)
- 10 g salt (2%)
Autolyse and mixing
Mix the flour with 325 g of the water until even, without starter or salt, cover and leave for 30–60 minutes. This is the autolyse: the flour absorbs the water and gluten starts to form by itself, without kneading. The dough turns smooth and stretchy.
Add the starter and work it in by hand, squeezing the dough through your fingers. Then add the salt with the remaining 25 g water and work it in again. Salt goes in after the autolyse because it slows down how fast flour absorbs water.
Stretch-and-folds instead of kneading
Wet sourdough isn't kneaded like ordinary dough. Instead you do sets of stretch-and-folds: they build gluten and trap gas.
Wet your hand, take the edge of the dough, pull it up until it resists and fold it over to the opposite side. Turn the bowl a quarter and repeat. Four folds make one set.
Do a set every 30 minutes, 4 sets over the first 2 hours. Each time the dough will get smoother, stronger and better at holding its shape.
Bulk fermentation: watch the dough, not the clock
After the folds, leave the dough covered. Total bulk fermentation at 24–26 °C is 4–6 hours; at 20–22 °C, 6–10 hours. Sourdough works more slowly than commercial yeast and depends heavily on temperature.
- The dough has grown by 50–75% (not doubled — that's over-fermented).
- The surface is domed, with bubbles visible on top and at the sides.
- The dough jiggles like jelly when you shake the bowl.
- The edges pull away from the sides of the bowl.
Shaping and cold proofing
Turn the dough onto a lightly floured counter. Shape it into a loose ball by folding the edges into the centre, and rest it for 20–30 minutes. Then do the final shape: flip it, fold it like an envelope and roll it into a tight log or ball, stretching the surface taut.
Put the dough seam-side up in a proofing basket or a bowl lined with a towel well dusted with rice flour (it doesn't absorb moisture, so the dough won't stick). Cover with a bag and refrigerate for 8–16 hours.
Cold proofing is the key to flavour and convenience. The dough ripens slowly, develops a complex tangy flavour, and cold dough is easier to turn out and score.
Baking in a cast-iron pot
A crackling crust and a high rise need steam for the first 20 minutes: a moist surface doesn't set and the bread can expand freely. At home the easiest way is a cast-iron pot with a lid — it traps the steam coming off the dough itself.
Put the pot with its lid in the oven and preheat to 250 °C for 45–60 minutes. Turn the dough out of the basket onto a sheet of baking paper and score it with a blade 5–10 mm deep at a 30–45° angle. Carefully lower the bread on its paper into the hot pot and put the lid on.
- 20 minutes at 250 °C with the lid on — the bread rises.
- Remove the lid, lower to 230 °C and bake 20–25 minutes more until the crust is deep brown.
- Done: tapping the bottom sounds hollow like a drum; the inside is 96–98 °C.
- Cool on a rack for at least 1–2 hours before slicing: the crumb is still setting inside and hot bread will be gummy.
Questions and answers
Why is there dark liquid on my starter?＋
That's hooch — alcohol released when the starter is hungry. It's harmless. Pour it off or stir it in (the bread will be more sour) and feed the starter.
My starter has gone mouldy — can I save it?＋
Fuzzy coloured mould on top — no, better start again. Pink or orange streaks — throw it away too. A white film with no fuzz is usually yeast; skim it off and feed the starter.
Why is my bread flat and dense?＋
A weak starter, under- or over-fermented dough, or loose shaping. Use the starter at peak activity, watch the dough's volume and stretch the surface tight when shaping.
What do I do with the discarded starter?＋
Add it to pancakes, fritters, crackers and pizza — it gives a pleasant tang. Keep the discard in a separate jar in the fridge for up to a week.
Can I bake without a cast-iron pot?＋
Yes: on a tray or stone at 250 °C, with a tray of boiling water on the bottom shelf for steam during the first 20 minutes. The crust will be a little thinner, but the loaf will still work.
More kitchen secrets
Sushi and rolls at home: restaurant-style rice, fillings and safe fish
Which rice to use and how to rinse it, the water ratio and seasoned vinegar, how to cool rice properly. How to roll maki and inside-out rolls that don't fall apart, which fish is safe raw, fillings without raw fish, baked rolls and storage.
Read the articleHow to assemble a cake at home: level layers, soaking syrup, smooth sides and drips
How to cut a sponge into even layers, how much soaking syrup each layer needs, why to pipe a dam and do a crumb coat, how to smooth a cake with a scraper, how much frosting a 20 cm cake needs, how to make chocolate drips, stack a tall cake and transport it in one piece.
Read the articleHomemade ice cream without a machine: rich vanilla, sorbet and banana ice cream
Two-ingredient ice cream with condensed milk, a classic custard-based vanilla, why ice crystals form and how to prevent them, sorbet with the right amount of sugar, frozen-banana ice cream, ice lollies and storage tips.
Read the article