How to Build, Maintain,
and Store Your Sourdough Starter
Your starter is the foundation of every loaf you’ll ever bake. This guide covers everything — building from scratch, feeding correctly, recognising the signs of a healthy culture, troubleshooting problems, and storing it whether you bake every day or once a month.
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A brand new starter often goes quiet around days 3–4 as different microorganisms compete before the right yeast and bacteria take hold. If your kitchen is below 68°F / 20°C, fermentation slows dramatically. Find a warmer spot — inside the oven with just the light on, or on top of the fridge. Switch to 100% whole wheat or rye flour for a few days, and make sure you’re using unbleached flour with filtered or rested tap water.
Full troubleshooting guide ›Bubbles are a good sign — fermentation is happening, but the yeast population isn’t dense enough yet to produce enough gas to double the volume. Add 20% rye flour to your next few feedings — rye has more wild yeast and minerals than any other common flour and often jumpstarts sluggish starters noticeably. Feed twice daily at 1:1:1 in a warm spot (75–80°F) and be patient. A new starter can take up to two weeks in a cool kitchen.
How to tell when it’s ready ›An acetone or alcohol smell means the starter has exhausted its food supply and the high acidity is now suppressing the yeast. This is not a sign the starter is ruined — it needs feeding urgently. Discard all but 20–30g and feed with fresh flour and water at a boosted ratio (1:2:2). Feed twice daily at room temperature for 2–3 days until the smell returns to pleasantly tangy and the rise is reliable. Prevent recurrence by feeding more frequently or using a larger ratio.
Maintenance schedules ›Hooch is alcohol produced when the starter runs out of food and yeast begins breaking down other compounds. It looks alarming but it isn’t. Pour it off or stir it back in (stirring it in will make your bread more sour), then feed your starter. If hooch is appearing frequently, your starter is getting hungry faster than you’re feeding it — increase feeding frequency or use a larger flour ratio like 1:2:2 or 1:3:3.
Pink or orange discoloration and fuzzy mould indicate harmful bacterial or fungal contamination, not the beneficial organisms you want. Discard the entire starter immediately — pink colouring in particular (Serratia marcescens) is a health concern. Thoroughly wash and sterilise all equipment before starting again. Note: grey liquid on top is just hooch and is normal. Only bright colour or fuzzy growth is cause to discard.
A previously reliable starter that suddenly stops performing almost always traces back to something that changed: the kitchen got colder as seasons shifted, you opened a new bag of flour, your water supply changed, or feedings were skipped. Go back to basics — twice daily feedings at 1:1:1, in the warmest spot in your kitchen, for 3–5 days. In almost every case the starter recovers fully. Change only one variable at a time so you can identify the culprit.
Full troubleshooting guide ›What Is a Sourdough Starter, Exactly?
A sourdough starter is a living culture of wild yeast and lactic acid bacteria, cultivated from nothing more than flour and water. Unlike commercial yeast — which is a single manufactured strain — a starter contains dozens of microorganisms working together. Wild yeasts produce carbon dioxide, which makes dough rise. Bacteria produce lactic and acetic acids, which give sourdough its distinctive flavour, its complex aroma, and its remarkable shelf life compared to commercially yeasted bread.
This living culture is what sets sourdough apart from every other bread. It also makes baking feel more personal — you’re not just following a recipe, you’re tending something alive that responds to your kitchen, your flour, and your schedule.
The good news: starters are far more resilient than most beginners expect. They survive neglect, cold temperatures, and missed feedings. They can be revived from the fridge after months. With proper storage they can last for decades.
What You’ll Need
Equipment
- A clear glass jar — 1-quart mason jars are ideal. Clear sides let you watch the rise without lifting the lid.
- A loose lid or cloth cover — the starter needs airflow. Don’t seal it airtight during active fermentation.
- A digital kitchen scale — essential for consistent ratios.
- A rubber band or tape — mark the level after each feeding to track rise without guessing.
- A non-reactive spoon — metal, silicone, or wood all work fine.
Ingredients
- Whole-grain flour (rye or whole wheat) for the initial days — these contain more wild yeast and minerals than refined flour, which jumpstarts fermentation significantly faster.
- Unbleached all-purpose or bread flour for ongoing maintenance — bleached flour can inhibit yeast activity.
- Filtered or rested tap water — let tap water sit uncovered for an hour before using, to allow chlorine to off-gas.
Building from Scratch: Days 1–7
Combine 60g of whole-grain flour (rye is ideal, whole wheat works well) with 60g of room-temperature water in your jar. Stir until completely smooth with no dry flour remaining. Cover loosely and leave at approximately 75°F / 24°C for 24 hours.
That’s it. You’re done for today.
Starting on Day 2, begin twice-daily feedings:
- Discard half the starter — this is necessary, not wasteful. It prevents the culture becoming too acidic.
- Add 60g of all-purpose flour and 60g of room-temperature water
- Stir vigorously until completely smooth
- Mark the level with your rubber band
- Cover loosely and leave at 75°F
In the first few days, bubbles may appear and then seem to disappear. This is normal. The early phase involves different microorganisms competing for dominance before the right bacteria and yeast establish themselves. Don’t panic if it goes quiet around Day 3 — this “lag phase” is part of every healthy starter’s development.
By days 5–7 in a warm kitchen, your starter should begin to behave predictably. You’re looking for:
- Visible rise after feedings — ideally doubling in size within 4–8 hours
- Abundant bubbles throughout, not just on the surface
- A pleasant, tangy smell — like yogurt, mild beer, or a hint of fruit
When your starter reliably doubles after feeding and passes the float test, it’s ready to bake with. In a cooler kitchen this may take 10–14 days — patience is the key variable.
Feeding Ratios: The Numbers That Matter
The ratio in which you feed your starter controls how quickly it ferments, how sour it becomes, and how long it takes to peak. Once you understand these, you can time your starter to be exactly ready when you need it.
| Ratio | Name | Peak Time at 75°F | Best Used For | |
|---|---|---|---|---|
| 1:1:1 | Standard | 4–8 hours | Daily bakers, consistent schedules | Most Common |
| 1:2:2 | Boosted | 6–10 hours | Warm kitchens, flexible timing | Slower |
| 1:3:3 | Extended | 8–12 hours | Overnight timing, cooler kitchens | Slower |
| 1:5:5 | Maintenance | 12–16 hours | Reducing discard frequency, away for a few days | Storage |
How to Know When Your Starter Is Ready to Bake With
The starter needs to be at peak activity when you use it — not before, not after. Peak is the moment the starter has risen to its maximum height and is still domed at the top. After peak, it begins to fall and the top turns slightly concave.
The Three Readiness Tests
1. The Doubling Test — mark the level right after feeding. Your starter is ready when it has at least doubled that mark and the top is still domed or flat. Beginning to recede means you’re just past peak — still usable but aim to catch it slightly earlier next time.
2. The Float Test — drop a teaspoon of starter into a glass of water. If it floats, it’s ready. If it sinks, it needs more time or another feeding cycle.
3. The Smell Test — a ready starter smells pleasantly tangy: yeasty, slightly sour, a little fruity. If it smells strongly of nail polish remover or acetone, it’s overripe and needs feeding before use.
Maintaining Your Starter: Building a Sustainable Routine
Once established, maintenance comes down to a simple principle: feed it before it gets too hungry, and use it when it’s at peak. The right schedule depends entirely on how often you bake.
If You Bake Several Times a Week
Keep your starter at room temperature and feed it once or twice daily. A twice-daily schedule (morning and evening) with a 1:1:1 ratio keeps a very active, always-ready starter. This is the approach for dedicated bakers who want maximum flexibility.
If You Bake Once a Week
Keep your starter in the refrigerator. Cold dramatically slows fermentation, so a weekly feeding is sufficient. The routine: take it out, discard all but 50g, feed with 50g flour and 50g water, let it sit at room temperature for 2–4 hours until it shows some activity, then put it back in the fridge. On baking day, take it out the night before, feed once, leave at room temperature overnight, and use it the following morning at peak.
If You Bake Less Than Once a Week
Refrigerator storage with weekly feedings still works well. Do two consecutive feedings the day before you plan to bake — one in the morning, one in the evening — to ensure the starter is fully reactivated and at full strength before it goes into your dough.
Long-Term Storage
Refrigerator (Weeks to Months)
The standard approach for most home bakers. Feed weekly minimum, or feed before refrigerating after a bake and it will keep comfortably for 1–2 weeks without attention. Before baking after a long fridge rest, do 1–2 refresher feedings at room temperature to bring it back to full activity.
Freezing (Up to 3 Months)
Ideal when going away for an extended period or as a backup. Feed your starter and let it peak. Portion it into 50–100g amounts in zip-lock bags or freezer containers and freeze. To revive: thaw at room temperature, discard to 50g, and feed once daily for 3–5 days until reliably active again. Don’t expect full activity on the first day — be patient.
Drying (Up to 1 Year)
The most shelf-stable option and what bakers traditionally used to preserve cultures long-term. Feed your starter and let it peak. Spread a thin layer (about 3mm) onto parchment paper and leave at room temperature for 24–48 hours until completely dry and brittle. Break into pieces and store in an airtight container in a cool, dark place. To rehydrate: combine with equal parts flour and water, feed once daily for 3–7 days. Dried starter takes longer to revive than frozen — plan ahead.
Troubleshooting Your Sourdough Starter
Hooch is alcohol produced when the starter runs out of food and yeast begins breaking down other compounds. It looks alarming — grey, sometimes dark brown — but is not harmful and doesn’t mean your starter is ruined.
Your starter is showing some activity but won’t double in size. This usually means the yeast population isn’t strong enough yet, or environmental conditions are working against it.
An acetone or strong alcohol smell means the starter is overripe — it has run out of food and the high acidity is now suppressing the yeast. This is very common in starters that haven’t been fed frequently enough, especially in warm weather.
Any pink or orange discoloration, or visible fuzzy mould, indicates contamination with harmful microorganisms — not the beneficial yeast and bacteria you’re cultivating. This is rare with regularly fed starters but can occur in very new cultures or those left a long time without feeding.
Most common in new starters, especially in cool kitchens. New starters in cool conditions can genuinely take 2–3 weeks before becoming reliably active — this is not a failure, it’s just biology operating at a slower pace.
Frequently Asked Questions
Sourdough Takes Time and Patience
Within a few weeks of consistent care, you’ll have a living culture that can leaven beautiful bread indefinitely — one that, with proper storage, could last for decades. The bakers who thrive with sourdough are the ones who observe more than they intervene. Watch your starter. Learn how it behaves in your kitchen, in your seasons, with your flour. It will tell you what it needs.
Get your starter right and everything else becomes significantly easier. Every flat loaf, every overproofed dough, every dull crust — most sourdough problems trace back to starter health. This is the foundation worth getting right first.