How Sourdough Feeding Ratios Work
A feed is written as three numbers — starter : flour : water — that tell you how much fresh food to give relative to the culture you keep. The classic 1:1:1 feed means equal weights of each: keep 50g of starter, stir in 50g of flour and 50g of water. Higher ratios like 1:5:5 give the same starter far more flour to eat, which dilutes the acids, slows the rise, and pushes the peak out to eight or twelve hours. The starter itself does not change — only how fast it climbs and how sour it tastes when it gets there. This calculator turns whatever ratio you pick into exact gram weights so the jar ends up at the size you actually want.
A Worked Example
Say a recipe needs 200g of active starter for a loaf. Feeding 70g of starter at 1:1:1 means adding 70g of flour and 70g of water, which gives 70 + 70 + 70 = 210g once it is fed. That covers the 200g the recipe pulls and leaves roughly 10g clinging to the jar to feed again and keep the culture going. If you would rather not throw anything away on the way there, keep a smaller amount — say 20g fed at 1:5:5 — the day before, so your maintenance jar grows into the larger build without a pile of discard.
Hydration and Why It Matters
Hydration is the weight of water divided by the weight of flour in your starter. A 100% hydration starter holds equal flour and water and pours like thick batter — it is the default most recipes assume and the easiest to keep. Drop to 80% or 60% and the starter turns into a stiff, doughy ball that ferments more slowly and tastes milder, the style behind an Italian lievito madre. The calculator lets you pick a hydration and splits the feed accordingly, so a stiff feed adds more flour than water while a wetter 125% feed does the reverse.
Sourdough Starter Feeding Calculator
Sourdough Feeding Ratio Guide
How feeding ratios affect rise time and flavor at room temperature (75°F / 24°C).
| Ratio (S:F:W) | Rise Time | Flavor Profile | Best For |
|---|---|---|---|
| 1:1:1 | 4-6 hours | Tangy, strong | Daily baking, quick turnaround |
| 1:2:2 | 6-8 hours | Mildly tangy | Twice-daily feeding, evening levain |
| 1:3:3 | 7-10 hours | Balanced | Overnight levain build |
| 1:5:5 | 8-12 hours | Mild, complex | Overnight levain, artisan bread |
| 1:8:8 | 10-14 hours | Very mild | Cold kitchen, slow fermentation |
| 1:10:10 | 12-16 hours | Mild, wheaty | Very slow builds, stiff starters |
| 1:1:1 (cold) | 12-24 hours | Tangy | Fridge retard after feeding |
| 1:5:5 (cold) | 24-48 hours | Complex, mild | Multi-day cold fermentation |
How to Use This Calculator
- Enter the Starter You Want to Keep: Type in the grams of existing starter you plan to carry forward — often 20g to 50g for a maintenance feed. This is the seed everything else scales from.
- Set Your Flour and Water Ratios: Enter the ratio relative to that starter. Use 1 and 1 for a fast 1:1:1 feed, or bump both to 5 for a slower 1:5:5 build. If you want a specific final amount, fill in the target total weight and let the calculator size the feed for you.
- Pick a Hydration: Leave it at 100% for a standard batter-like starter, or choose 80% or 60% for a stiffer, milder culture. This decides how the feed splits between flour and water.
- Calculate and Feed: Press Calculate to see exactly how much flour and water to add and what the jar will weigh once fed. Weigh out those amounts, stir until no dry flour remains, and mark the jar so you can watch it rise to peak.
How It Works
Sourdough starter feeding ratios determine how much flour and water to add relative to the amount of starter you keep. The ratio affects fermentation speed, flavor, and rise timing.
The basic rule:
- 1:1:1 (starter:flour:water) — fast rise, good for daily baking. Peaks in 4-6 hours at 75°F.
- 1:2:2 — moderate rise, mild flavor. Peaks in 6-8 hours. Good for overnight levains.
- 1:5:5 — slow rise, more developed flavor. Peaks in 8-12 hours. Great for timing overnight bakes.
- 1:10:10 — very slow rise. Peaks in 12-16 hours. Best for cold environments or less-active starters.
Higher ratios (more flour and water relative to starter) produce a milder, slower-rising starter. Lower ratios produce a faster, more sour starter. Adjust your ratio to match your baking schedule.
Tips & Considerations
- Feed at peak, not on a clock. A starter is ready when it has roughly doubled and the domed top just begins to flatten — feeding it then keeps it strong.
- Weigh everything in grams. Volume measures for flour swing wildly, and a starter's whole personality lives in the flour-to-water balance.
- To bake without a discard pile, plan a day ahead: carry a small amount at a high ratio like 1:5:5, then step up to the full build the night before you mix dough.
- A neglected fridge starter often smells sharp and looks flat. Two or three feeds at 1:5:5, a few hours apart in a warm spot, usually bring it back before you trust it in dough.
- Warm kitchens speed everything up. In summer, lean on higher ratios or cooler water so the starter does not peak and collapse before you are ready to use it.
- Keep a backup: dry a thin smear of active starter on parchment, crumble it into a jar, and you can rehydrate a fresh culture if your main jar ever dies.
Frequently Asked Questions
What is a 1:1:1 feed?
It means equal weights of starter, flour, and water. Keep 50g of starter, add 50g of flour and 50g of water, and you end up with 150g of fed starter. It is the standard maintenance feed and rises quickly — usually peaking in 4 to 6 hours at room temperature.
What does hydration mean for a starter?
Hydration is the water weight divided by the flour weight, expressed as a percent. Equal flour and water is 100% hydration and gives a batter-like starter. Less water — say 80% or 60% — makes a stiff, dough-like starter that ferments more slowly and tastes milder.
How much starter should I feed before baking?
Work backward from what the recipe needs plus a little to keep the jar going. For a loaf that wants 200g of levain, feeding 70g of starter at 1:1:1 gives you 210g — enough for the recipe with a small amount left to feed again. Enter your target total in the calculator and it sizes the feed automatically.
Why would I use a higher ratio like 1:5:5?
A bigger flour-and-water feed dilutes the acids in the old starter and gives the yeast more to eat, which slows the rise to 8 to 12 hours and develops a milder, more complex flavor. It is handy for overnight levains and for reviving a sluggish or over-sour starter.
How often should I feed my starter?
At room temperature, feed once or twice a day, always before it fully collapses. In the fridge, once a week is plenty. If you bake rarely, keep only a small amount — 20g or so — and feed at a higher ratio to reduce waste between bakes.
How do I avoid throwing away so much discard?
Keep a smaller maintenance amount and use higher feeding ratios, then scale up only in the day or two before you bake. A 20g starter fed 1:5:5 becomes 240g without ever discarding, and any leftover fed starter still works in pancakes, waffles, or crackers.
How do I know my starter is ready to use?
It should have roughly doubled, show a domed top full of bubbles, and smell pleasantly tangy rather than sharp or boozy. A spoonful that floats in water is a good sign. Use it at peak rise, just before the surface starts to sink back down.