Sourdough Starter Feeding Ratios Explained

A sourdough starter feeding ratio tells you how much old starter, flour, and water to combine for each feed — expressed as three numbers in the format starter : flour : water, always by weight. The ratio you choose directly controls how fast your starter peaks, how acidic it becomes, and how convenient it fits into your baking schedule.

What Does 1:1:1 Mean?

A 1:1:1 ratio means equal parts old starter, flour, and water by weight. If you use 20g of old starter, you add 20g of flour and 20g of water. Total after feeding: 60g.

This is the most common ratio for active bakers. It gives the culture a reasonable food supply relative to the amount of existing yeast and bacteria, so it peaks relatively quickly — typically 4–6 hours at 24°C (75°F).

When to use 1:1:1:

• Same-day baking (morning feed, bake in the afternoon)
• Reviving a sluggish starter (more frequent food)
• Maintaining a very active culture on a daily schedule

What Does 1:2:2 Mean?

A 1:2:2 ratio means one part old starter to two parts flour and two parts water. Keep 20g starter, add 40g flour and 40g water. Total: 100g.

The larger food supply means it takes longer to peak — typically 6–10 hours at 24°C. This is a good overnight ratio: feed in the evening, use the starter the next morning.

What Does 1:5:5 Mean?

A 1:5:5 ratio means one part old starter to five parts flour and five parts water. Keep 10g starter, add 50g flour and 50g water. Total: 110g.

This is a slow-build ratio. Peak timing at 24°C is typically 10–14 hours. The large food supply relative to the seed dilutes the existing acid in the culture and produces a milder-flavoured starter at peak.

When to use 1:5:5:

• Long overnight builds (feed late evening, ready to use next morning or afternoon)
• When you want a less acidic loaf
• When your kitchen is warm and a 1:1:1 peaks too fast

How Ratio Affects Peak Timing

The relationship between ratio and peak timing is roughly proportional at the same temperature. Doubling the food (from 1:1:1 to 1:2:2) roughly doubles the time to peak. Going from 1:1:1 to 1:5:5 extends peak time by roughly 3–4×.

Temperature has a larger effect than ratio — a change of 4°C can halve or double peak time regardless of ratio. Use the sourdough feeding calculator to plan your feeds around your baking schedule.

How Ratio Affects Flavour

A lower ratio (less food per unit of starter) means the culture eats through its food faster and builds acid more quickly. The result is a tangier, more assertive flavour. Bakers who want a very sour loaf often use a 1:1:1 ratio and let the starter go slightly past peak before using it.

A higher ratio (more food) dilutes the acid and produces a milder starter at peak. Bakers who prefer a less sour loaf — or who want to highlight the flavour of a specific grain — tend to use 1:5:5 or even higher ratios.

Hydration and Ratio Are Separate Things

The feeding ratio (starter : flour : water) describes the proportions of each ingredient. The hydration of the starter (water as a percentage of flour) is a separate property.

In a 1:1:1 ratio with equal flour and water, the resulting starter is 100% hydration. But you can run a 1:2:2 ratio with more water than flour to get a looser starter:

• 1:2:3 → 150% hydration (very loose, liquid-like)
• 1:2:2 → 100% hydration (standard)
• 1:2:1.6 → 80% hydration (stiffer)

Stiff starters (50–70% hydration) tend to produce a more acidic flavour and have a more compact structure. Liquid starters (100–150% hydration) are more active and produce a more open, bubbly culture. Most home bakers use 100% hydration because it’s easy to calculate and observe.

Custom Ratios

There’s nothing magic about 1:1:1 or 1:5:5 — they’re just round numbers that are easy to remember and calculate. You can use any ratio that fits your schedule.

For example:

• 1:3:3 is a good middle ground for bakers who want an 8–10 hour window
• 1:1:2 produces a looser 200% hydration starter with a faster peak than 1:2:2
• 2:5:5 is sometimes used to maintain a larger volume of starter without discarding as much

The key is consistency — pick a ratio, stick to it, and observe how your starter behaves. Once you know your starter’s timing at a given ratio and temperature, you can plan your bakes precisely.

Which Ratio Should You Use?

If you bake every day or two: 1:1:1 on the counter, once daily.

If you bake 2–3 times per week: 1:2:2 or 1:3:3 on the counter, once daily. Feed in the evening, use in the morning.

If you bake once a week: Store in the fridge. Feed 1:5:5 before baking, let it peak at room temperature, use, then return to fridge.

If you want maximum sourness: Use 1:1:1 and let the starter go slightly past peak before using.

If you want minimum sourness: Use 1:5:5 and use the starter right at peak.

FAQs

Does the ratio have to be the same for flour and water? No. The ratio format is starter : flour : water. You can use different flour and water amounts to control hydration. 1:2:3 means one part starter, two parts flour, three parts water — a 150% hydration starter.

Can I use a 1:10:10 ratio? Yes, but only for a healthy, active starter. A very weak or sluggish culture won’t be able to metabolise that much food and will peak poorly. Build up to high ratios gradually.

What happens if I use more starter than the ratio suggests? More old starter means more existing yeast and bacteria — the culture peaks faster. It also means more accumulated acid from the old starter, which can produce a more sour result and a faster collapse after peak.

Why does my 1:5:5 starter taste more mild than my 1:1:1? Because the large food supply relative to the starter seed dilutes the acid load and gives the culture more time to produce a balanced mix of lactic acid (mild, yogurt-like) and acetic acid (sharp, vinegary). The milder result at peak is expected — if you want more tang at 1:5:5, let it go a little past peak before using.

How do I calculate how much to feed? Use the sourdough feeding calculator — enter the ratio, your target amount, and it gives you exact grams of starter, flour, and water to use.