When sourdough bakers talk about feeding their starter at a "1:1:1 ratio" or "1:5:5," they're describing how much starter, flour, and water to mix together. The three numbers always follow the same order:
A 1:1:1 ratio means equal parts by weight — 50g starter, 50g flour, 50g water. A 1:5:5 ratio means 1 part starter to 5 parts flour and 5 parts water — so 20g starter, 100g flour, 100g water.
This is the same concept as baker's percentages, where every ingredient is expressed as a ratio relative to a base ingredient (flour for bread, starter for sourdough feeding).
The most common maintenance feeding. Keeps the yeast and bacteria populations balanced and the starter mild-flavored.
| Starter | Flour | Water | Total |
|---|---|---|---|
| 50 g | 50 g | 50 g | 150 g |
| 100 g | 100 g | 100 g | 300 g |
Best for: Daily feeding when kept at room temperature, or weekly feeding if refrigerated. Peaks in 4–8 hours at room temp depending on starter strength and ambient temperature.
A slightly more dilute feeding that extends the time to peak. More flour and water relative to starter means the yeast has more food to work through.
| Starter | Flour | Water | Total |
|---|---|---|---|
| 50 g | 100 g | 100 g | 250 g |
| 25 g | 50 g | 50 g | 125 g |
Best for: When you need a longer window before the starter peaks, or when a young starter is too acidic and needs to be mellowed out.
A high ratio used for building up a large amount of starter quickly, or for slowing down a very active starter.
| Starter | Flour | Water | Total |
|---|---|---|---|
| 20 g | 100 g | 100 g | 220 g |
| 10 g | 50 g | 50 g | 110 g |
Best for: Building a large batch for baking day (called a "levain build"), or when your starter is too strong and peaking too quickly. Peaks in 8–12 hours depending on conditions.
Extreme dilution, typically used for a single pre-bake build when you need a lot of starter from a small amount, or for rebalancing an overly acidic starter.
| Starter | Flour | Water | Total |
|---|---|---|---|
| 10 g | 100 g | 100 g | 210 g |
| 5 g | 50 g | 50 g | 105 g |
Best for: Levain builds when you only have a small amount of starter, or when trying to revive a neglected, overly sour starter.
Start with the amount of starter you want to end up with (your target total), then work backward using the ratio.
The ratio 1:2:2 adds up to 5 parts (1 + 2 + 2). Divide your target by 5 to find one part: 250g ÷ 5 = 50g per part.
Starter: 1 part = 50g · Flour: 2 parts = 100g · Water: 2 parts = 100g
For any ratio X:Y:Z and target weight T:
Then multiply each number in the ratio by "one part" to get the ingredient weights. This is the same math you'd use when scaling any recipe by baker's percentages.
Ratio adds up to 11 parts (1 + 5 + 5). One part = 300g ÷ 11 ≈ 27g.
Ratio adds up to 3 parts. One part = 150g ÷ 3 = 50g.
Ratio adds up to 9 parts. One part = 500g ÷ 9 ≈ 56g.
There are two contexts where you feed a sourdough starter, and they use different ratios:
Keeping your starter alive between bakes. You discard most of the starter (or use it in discard recipes), then feed what's left. The goal is to keep the yeast and bacteria healthy without accumulating an enormous jar of starter.
Typical ratios: 1:1:1 or 1:2:2
Amount needed: Just enough to keep in the jar — usually 100–150g total is plenty
Frequency: Daily if at room temperature, weekly if refrigerated
Building up a large amount of active starter specifically for baking. You start with a small amount of your maintenance starter and feed it at a higher ratio to scale up to the amount your recipe needs. This is usually done 4–12 hours before mixing your dough, so it peaks right when you're ready to bake.
Typical ratios: 1:3:3, 1:5:5, or even 1:10:10
Amount needed: Whatever your recipe calls for (often 200–400g) plus a little extra to keep as your maintenance starter
Frequency: Only when you're about to bake
Most sourdough recipes assume a 100% hydration starter — equal parts flour and water by weight, which is what a 1:1:1 or 1:5:5 ratio produces. Some bakers maintain stiffer (60–80% hydration) or wetter (125%+) starters for specific bread styles.
To calculate your starter's hydration (the same formula used in our bread hydration guide):
In a 1:1:1 feeding (50g starter, 50g flour, 50g water), the new mixture has 50g flour and 50g water = 100% hydration. If you feed 1:2:1 (50g starter, 100g flour, 50g water), the result is 50% hydration — a stiffer starter.
Most recipes are written for 100% hydration starters. If yours is different, you'll need to adjust the flour and water in the bread recipe itself to compensate.
If your starter lives on the counter, feed it every 24 hours at 1:1:1. It will peak (double in size, bubbly, domed top) in 4–8 hours, then gradually deflate. Feed it again before it collapses completely.
For occasional baking, keep your starter in the fridge and feed it once a week. Pull it out, discard most of it, feed at 1:1:1, let it sit at room temp for an hour or two to wake up, then return it to the fridge. When you want to bake, take it out the night before, let it warm up, and do a levain build.
Feed your starter (or do a levain build) so it peaks right when you're ready to mix your dough. Most recipes want the starter at or just past peak — fully risen, domed on top, lots of bubbles. If you use it too early (still rising) or too late (collapsed, separated liquid on top), the bread won't rise as well.
Your starter is very strong, or your kitchen is warm. Switch to a higher ratio (1:3:3 or 1:5:5) to give it more food and slow it down, or move it somewhere cooler.
Starter is weak, cold, or underfed. Try a lower ratio (1:1:1) to concentrate the yeast, or move it somewhere warmer (75–80°F is ideal). If it's been neglected, it may need several daily 1:1:1 feedings to regain strength.
It's overly acidic from being underfed or left too long. Pour off any liquid (called "hooch"), then feed at a high ratio (1:5:5 or 1:10:10) to dilute the acidity. Do this for 2–3 feedings in a row to rebalance it.
Either it's too cold (below 65°F, yeast is sluggish), it's been neglected for weeks and needs revival, or it's contaminated. Try a few daily 1:1:1 feedings at room temp (75–80°F). If it still doesn't rise after a week, it may be dead — start over.
You may be using the starter too early (before it peaks) or too late (after it collapses). For best results, use it at peak or within an hour or two past peak — it should be domed on top, doubled in size, and full of bubbles.
| Ratio | Use case | Time to peak (room temp) |
|---|---|---|
| 1:1:1 | Daily maintenance, standard feeding | 4–8 hours |
| 1:2:2 | Stretching time to peak, mellowing acidity | 6–10 hours |
| 1:3:3 | Levain build, moderate scaling | 8–10 hours |
| 1:5:5 | Large levain build, slowing a strong starter | 8–12 hours |
| 1:10:10 | Reviving neglected starter, emergency levain build | 12+ hours |
Sunday: Pull starter from fridge. Discard all but 50g. Add 50g flour + 50g water (1:1:1). Stir, let sit at room temp for 1–2 hours, then return to fridge.
Friday (bake day): Pull starter from fridge in the evening. Discard all but 20g. Add 100g flour + 100g water (1:5:5). Let sit overnight at room temp. By morning it's peaked and ready to bake with. After mixing your dough, keep 50g of the levain, feed it 1:1:1, and return it to the fridge.
Every morning: Starter from yesterday has peaked and started to deflate. Discard all but 50g. Add 50g flour + 50g water (1:1:1). Stir, leave on counter. By evening it's peaked. The next morning, repeat.
Bake day: Instead of discarding, use the peaked starter directly in your recipe (if it's the right amount), or do a levain build at 1:3:3 to scale it up.
Bread Hydration: What Baker's Percentages Actually Mean — Sourdough starter ratios use the same percentage logic as bread hydration.
How to Scale Baking Recipes Up or Down — The same ratio math applies to scaling starter feedings.
The Best Kitchen Scales for 2026 — Feeding by weight is essential for consistent sourdough starter ratios.