How to Feed a Sourdough Starter: 1:1:1, 1:2:2, 1:5:5 Ratios Explained

Quick answer: sourdough feeding ratios are written as starter : flour : water by weight. A 1:2:2 feed using 20 grams of starter means 20 grams starter, 40 grams flour, and 40 grams water.

One of the most useful things to understand about sourdough is that a feeding ratio is not a magic recipe. It is a scheduling tool. Changing the amount of fresh flour and water relative to the amount of starter changes how much food the culture has available and usually changes how quickly it reaches its peak.

My starter, Ursula, is the culture behind STUpendous Sourdough. Keeping a starter useful is less about memorizing one feeding forever and more about understanding what the numbers mean so you can adjust intelligently.

How to read a sourdough feeding ratio

The ratio is starter : flour : water. Always read it in that order.

1:1:1 feeding

Example: 20 grams starter + 20 grams flour + 20 grams water = 60 grams total starter after feeding.

This is a relatively small refresh. Because the carried-over starter is a large portion of the mixture, an active culture can work through the fresh food comparatively quickly.

1:2:2 feeding

Example: 20 grams starter + 40 grams flour + 40 grams water = 100 grams total starter after feeding.

This gives the culture twice as much fresh flour and water for the same seed amount. It often gives you more time before peak than 1:1:1.

1:5:5 feeding

Example: 10 grams starter + 50 grams flour + 50 grams water = 110 grams total starter after feeding.

This is a larger refresh. It can be useful when you want a longer runway before the starter peaks, provided the starter is healthy enough for the feed and your temperature supports the schedule.

How feeding ratio changes timing

• More seed starter relative to fresh food usually means a faster peak.

• More fresh flour and water relative to seed starter usually means a slower peak.

• Warmer temperatures generally speed fermentation.

• Cooler temperatures generally slow fermentation.

• A strong, recently active starter may behave differently from one that has been refrigerated or neglected.

• Flour choice can change activity, aroma, texture, and timing.

This is why exact clock times are not universal. Two jars fed at the same ratio can still peak at different times if their temperatures, flour, or starter condition differ.

How to feed a starter by ratio

1. Choose how much seed starter you want to keep.

2. Multiply that seed amount by the flour number in your chosen ratio.

3. Multiply the seed amount by the water number in your chosen ratio.

4. Mix until no dry flour remains and mark the starting level on the jar.

5. Watch the starter for expansion, bubbles, a rounded or domed top near peak, and a clean fermented aroma.

6. Use or feed it based on the recipe and the stage of activity you need.

Feeding ratio is different from dough hydration

A 1:2:2 feeding has equal flour and water in the fresh feed, which is commonly described as a 100 percent hydration feed because the water weight equals the flour weight. That is separate from the hydration of your final bread dough, where water is calculated relative to the total flour in the dough formula.

What should an active starter look like?

• It expands noticeably after feeding.

• Bubbles appear throughout the jar, not just on the surface.

• The texture becomes aerated and lighter as fermentation progresses.

• Near peak, the top may look rounded or just begin to flatten.

• The aroma should smell fermented and pleasantly acidic rather than rotten or putrid.

Do not judge starter strength from one bubble or one exact hour. Repeated behavior is more useful than a single snapshot.

Related sourdough guides

New to the whole process? Start with The Ultimate Beginner's Guide to Sourdough.

Trying to understand what you remove before feeding? Read What Is Sourdough Discard?.

Once your starter is active, the next skill is reading the dough. See Sourdough Fermentation Explained.

Frequently Asked Questions

What does a 1:1:1 sourdough feeding ratio mean?

It means equal weights of starter, flour, and water. For example, 20 grams of starter plus 20 grams of flour plus 20 grams of water.

What does a 1:2:2 feeding ratio mean?

It means one part starter, two parts flour, and two parts water by weight. For example, 20 grams of starter plus 40 grams of flour plus 40 grams of water.

Why use a larger feeding ratio such as 1:5:5?

A larger feeding gives the microorganisms more fresh flour and water relative to the amount of old starter. It generally takes longer to consume that food, so the starter often takes longer to reach its peak.

Should sourdough feeding ratios be measured by weight or volume?

Weight is the clearest method because flour and water do not occupy equal volumes. A digital kitchen scale makes feeding ratios simple and repeatable.

Is 1:1:1 always the best feeding ratio?

No single ratio is best for every schedule or starter. A smaller feed can peak sooner, while a larger feed can give you a longer runway. Temperature and starter condition also matter.

The STUpendous takeaway

Feed ratios give you control. The goal is not to prove that one ratio is superior. The goal is to understand the relationship between seed starter, fresh food, temperature, and time so your starter can fit your baking schedule instead of your life revolving around a jar of flour and water.