Work out the flour and water to add when feeding your sourdough starter at a set ratio.
Usage Tip
Discard down to your starter weight before feeding to keep quantities manageable.
What is a sourdough starter?
A sourdough starter is a living culture of flour and water colonised by wild yeast and lactic-acid bacteria. Fed regularly, it ferments – the yeast produces gas to leaven bread and the bacteria add the tangy sourdough flavour. A healthy mature starter roughly doubles within 4–8 hours of feeding.
Common feeding ratios
A feeding ratio is written starter : flour : water. 1:1:1 means equal weights of each; 1:5:5 means five parts flour and water for every one part of existing starter. A bigger ratio means more fresh food per bit of starter, so it ferments slower – handy for warm kitchens or longer gaps between feeds.
Feeding ratio chart
| Ratio | Starter | Flour | Water |
|---|---|---|---|
| 1:1:1 | 50 g | 50 g | 50 g |
| 1:2:2 | 50 g | 100 g | 100 g |
| 1:3:3 | 50 g | 150 g | 150 g |
| 1:5:5 | 20 g | 100 g | 100 g |
Starter feeding guide
To feed, keep a small amount of starter, discard the rest, then add fresh flour and water at your chosen ratio. Stir, mark the level, and leave it to rise. Feed once a day at room temperature, or once a week if stored in the fridge.
Starter hydration guide
Hydration is the water as a percentage of flour. Most starters are kept at 100% hydration (equal flour and water), which is easy to feed and read. A stiff starter (50–60%) ferments slower and keeps longer; a wetter starter (over 100%) is more active and sour.
Sourdough discard guide
“Discard” is the starter you remove before feeding to keep the jar from growing endlessly. It is perfectly usable – do not throw it away if you can bake with it.
Discard uses
- Pancakes and waffles
- Crackers and flatbreads
- Banana bread and muffins
- Pizza dough and focaccia
- Pasta and crumpets
Starter build & levain examples
A levain is an off-shoot of your starter built specifically for a bake. To build a 200 g levain at 1:4:4, take 25 g starter and add 87.5 g flour and 87.5 g water. Build it the night before and use it at peak.
| Levain target | Ratio | Starter | Flour | Water |
|---|---|---|---|---|
| 150 g | 1:2:2 | 30 g | 60 g | 60 g |
| 200 g | 1:4:4 | 22 g | 89 g | 89 g |
| 300 g | 1:5:5 | 27 g | 136 g | 136 g |
Maintenance schedule
Counter (active baking)
Feed once or twice a day at a 1:1:1 to 1:5:5 ratio depending on temperature. Keep at room temperature for a ready-to-bake starter.
Fridge (occasional baking)
Feed, let it start to rise, then refrigerate. Feed once a week. Bring out and feed 1–2 times before baking.
Starter maturity guide
- Days 1–3: Mix flour and water; early bubbles, often a false rise from other bacteria.
- Days 4–7: Activity may stall then restart as the culture balances; vinegary smell settles.
- Days 7–14: Predictable rise and fall, pleasant sour-yeasty aroma.
- Weeks 2–4+: Mature – reliably doubles in 4–8 hours and is strong enough to leaven bread.
Refrigeration & storage
For storage, refrigerate a fed starter in a loosely covered jar; it slows right down and only needs weekly feeding. For longer breaks, dry a thin layer of starter and store the flakes airtight, or freeze a portion. Both can be revived later.
Starter revival instructions
To wake a neglected starter, discard all but a tablespoon, feed 1:5:5, and keep it warm. Repeat daily – even one that has separated with dark liquid (“hooch”) usually bounces back within 2–3 feeds. Dried starter is rehydrated with equal water, then fed normally.
Temperature recommendations
| Temperature | Effect |
|---|---|
| 75–82°F (24–28°C) | Ideal – fast, balanced fermentation |
| 65–75°F (18–24°C) | Slower; feed less often |
| Below 50°F (10°C) | Dormant (fridge storage) |
Sourdough troubleshooting
Liquid on top (hooch)
It is hungry – pour off the liquid and feed more often or at a bigger ratio.
No rise
Too cold, too young, or underfed. Warm it up and feed daily; give a new starter 1–2 weeks.
Smells like acetone
Underfed – feed more frequently or at a higher ratio.
Pink/orange streaks or fuzzy mold
Discard it – that is spoilage, not normal sourdough, and the starter should be started fresh.
Printable feeding chart
| Keep starter | 1:1:1 | 1:2:2 | 1:5:5 |
|---|---|---|---|
| 20 g | +20/+20 | +40/+40 | +100/+100 |
| 50 g | +50/+50 | +100/+100 | +250/+250 |
| 100 g | +100/+100 | +200/+200 | +500/+500 |
Values are flour/water added in grams.