Sourdough Feeding Ratios Explained: 1:1:1, 1:2:2, and More

The three numbers in a sourdough feeding ratio tell you how much starter, flour, and water to combine at each feeding. Once you know what they mean, you can adjust your schedule without guessing.

What the Three Numbers Actually Mean

The ratio is always written as starter : flour : water, in that order. Each number is a relative weight, not a fixed gram amount. So 1:1:1 means equal weights of all three; 1:2:2 means one part starter to two parts flour and two parts water.

Here is a concrete way to read it: if the first number is 1, multiply the other numbers by however many grams of starter you are using.

• 1:1:1 with 20 g starter: 20 g starter + 20 g flour + 20 g water
• 1:2:2 with 20 g starter: 20 g starter + 40 g flour + 40 g water
• 1:5:5 with 20 g starter: 20 g starter + 100 g flour + 100 g water

The ratio does not change the hydration of your starter (flour and water stay equal when both numbers match), but it does change how much food you are giving the culture relative to its size.

If you are new to keeping a starter alive, how to feed and maintain a sourdough starter walks through the full routine in plain terms.

Gram Examples for Common Ratios

The table below shows three popular ratios using a 20 g starter as the base. Adjust the gram amounts up or down depending on how much starter your recipe calls for.

Ratio	Starter (g)	Flour (g)	Water (g)	Total (g)
1:1:1	20	20	20	60
1:2:2	20	40	40	100
1:5:5	20	100	100	220

A few notes on the numbers:

• Total jar size matters. At 1:5:5, a 20 g starter becomes 220 g after feeding. Make sure your jar can hold twice the fed volume to give the starter room to rise.
• You do not have to keep 20 g of starter. Many bakers keep as little as 5 to 10 g between feedings to cut down on discard. Just scale the flour and water to match your chosen ratio.
• Flour blend is up to you. Using all-purpose, bread flour, or a mix of white and whole wheat all work. Whole wheat and rye ferment faster because they carry more wild yeast and bacteria naturally.

How the Ratio Changes Your Timeline

The core idea: a larger ratio means more food per unit of starter, which slows the peak.

At 1:1:1, the yeast and bacteria have a relatively small amount of fresh flour to work through. In a warm kitchen (24 to 26 C), the starter will peak in roughly 4 to 6 hours. This is a good ratio when you want to bake the same day or when your starter needs a quick turnaround.

At 1:2:2, the culture has twice as much flour to consume. Peak time in the same warm kitchen stretches to roughly 6 to 10 hours, depending on starter health and temperature. This fits a morning-feed, evening-bake schedule for many people.

At 1:5:5, the starter peaks slowly, often 10 to 14 hours at room temperature. Some bakers use this ratio overnight in a cool kitchen (18 to 20 C) so the starter is ready in the morning without having to wake up to check it.

These are starting-point ranges. Your kitchen, your flour, and the age and vigor of your starter all shift the actual timeline. The best way to learn your starter's rhythm is to watch it rather than rely on the clock alone.

If your starter is not rising predictably regardless of which ratio you use, why your sourdough starter isn't rising and how to fix it covers the most common reasons.

Choosing a Ratio for Your Schedule

The practical question is: when do you want your starter to peak?

Baking same-day: A 1:1:1 or 1:2:2 ratio in a warm spot (25 C or above) will give you a ripe starter in time for an afternoon or evening bake if you feed it in the morning. The smaller ratio works well in summer or if your kitchen runs warm.

Baking next morning: A 1:5:5 ratio at room temperature overnight (roughly 18 to 21 C) is a common approach. You feed before bed and the starter peaks around the time you wake up. If your kitchen is warmer than 21 C overnight, drop to a 1:3:3 or 1:4:4 so it does not over-ferment and collapse before morning.

Maintaining without baking: If you are not baking for a few days, a 1:5:5 or even 1:10:10 ratio with refrigeration keeps the starter stable longer between feedings. The large ratio gives the culture plenty of food to slowly work through in the cold.

A rough guide:

Kitchen temp	Good overnight ratio
Below 18 C	1:3:3 or 1:4:4
18 to 21 C	1:5:5
22 to 25 C	1:5:5 to 1:7:7
Above 25 C	1:7:7 to 1:10:10

These are starting points. Watch how quickly your starter peaks after a few feedings and adjust from there.

How Ratio Interacts with Starter Health

A young or sluggish starter often benefits from a 1:1:1 ratio for a few consecutive feedings. The quick turnaround keeps the culture active and gives you frequent chances to check its behavior without wasting flour.

A mature, vigorous starter can handle larger ratios without losing activity. If you push a weak starter to 1:5:5 too soon, the yeast population may not be dense enough to work through all that flour, and the starter can stall or produce off flavors.

Signs your starter is healthy enough for larger ratios:

• Doubles reliably within 4 to 8 hours at a 1:1:1 feeding
• Shows a domed top at peak rather than a flat or sunken surface
• Smells pleasantly sour or yeasty, not like nail polish remover (acetone) or paint

If you are still building a new culture from scratch, how to make a sourdough starter from scratch covers the early days before ratios become the main variable.

A Note on Hydration

When both the flour number and water number are equal (1:1:1, 1:2:2, 1:5:5), you are feeding a 100% hydration starter, meaning equal weights of flour and water. This is the most common style for home bakers because it is easy to calculate and produces a pourable, thick-batter consistency.

If a recipe calls for a stiffer starter (like 65 to 70% hydration), you would adjust the water number lower. For example, a 1:2:1.3 ratio gives roughly 65% hydration on the fresh feed. Most beginner recipes assume 100% hydration, so unless your recipe says otherwise, keep the flour and water numbers equal.

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Frequently Asked Questions

Does the ratio I use affect the flavor of my bread?

Yes, to a degree. A slower, cooler fermentation from a larger ratio tends to develop more acetic acid (sharper, vinegary tang). A faster fermentation from a smaller ratio or a warm kitchen favors lactic acid (milder, yogurt-like sourness). If you want a more pronounced sour flavor, try a 1:5:5 overnight feed in a cool kitchen before baking.

Can I use different flours in my feeding ratio?

You can. Many bakers use a blend, like 80% all-purpose and 20% whole wheat rye. The ratio math stays the same; just weigh the total flour amount and split it however you like. Whole grain flours speed up fermentation, so if you add more of them, your starter will peak sooner than it did on plain white flour.

How much starter should I keep on hand?

That depends on your baking frequency. Most recipes call for 50 to 200 g of ripe starter at a time. Many home bakers keep a small maintenance culture of 10 to 30 g and scale up the day before baking by feeding with more flour and water. This reduces how much discard you produce between bakes.

What happens if I miss a feeding?

A mature starter kept at room temperature will survive a missed feeding, though it will smell more acidic and may show liquid (called "hooch") on top. Pour off the hooch or stir it back in, discard most of the starter, and do one or two 1:1:1 feedings to bring it back to peak activity before you bake. If you store your starter in the refrigerator, it only needs feeding once a week.

Does the ratio change how I use the starter in a recipe?

No. The recipe specifies how much ripe starter to add to the dough. The ratio is only about how you feed and time the starter beforehand. Once the starter has peaked at any ratio, it behaves the same way in the dough as long as it is at 100% hydration (or whatever hydration the recipe expects).