Sourdough Starter Feeding Ratios

Maintaining a sourdough starter requires regular feedings to keep the active culture of yeasts and bacteria alive. These refreshments provide new food for the microorganisms, allowing them to thrive and produce the by-products that flavor and leaven bread. But how much flour and water should you use when feeding your starter? Should it always be the same amount? And what happens if you change the amount? Let's explore how the amount you feed your starter can influence the fermentation rate, and by the end, you’ll know how to adjust your feeding routine to fit your baking routine and goals.

What is a Sourdough Starter Feeding Ratio?

When you refresh your starter, the portion of the mature starter that is carried over into the next feeding is often referred to as the “seed.” This is because it contains the living microbes that will carry on into the new culture when flour and water are added. Bakers often use the term "feeding ratio” or “seed ratio” to refer to the proportion of sourdough starter, flour, and water used when feeding the starter. It is important to note that the ratio is based on weight, not volume.

Feeding ratios are written as three numbers—the first representing the “seed” starter, the second representing the flour, and the third representing the water. For instance, a 1:1:1 ratio means using equal parts by weight of starter, flour, and water.

Example feeding ratios expressed in ratios and how they could be expressed in weight:

• 1:1:1 Ratio: 50g starter, 50g flour, 50g water
• 1:2:2 Ratio: 10g starter, 20g flour, 20g water
• 1:4:4 Ratio: 30g starter, 120g flour, 120g water
• 1:8:8 Ratio: 5g starter, 40g flour, 40g water

As you can see in the above examples, both the amount of starter and the amount of flour and water can be adjusted to achieve the desired ratio.

Why does the feeding ratio matter?

Understanding the concept of feeding ratio is important because it directly influences the rate at which your starter will peak. The basic idea is that when less food is available to the microbes, your starter will ripen faster, and when there is more food, it will take longer to ripen.

So, how can you tell by looking at the ratio? A quick rule of thumb is this:

The first number will always be 1 (your “seed” starter).
The larger the second and third numbers are, the higher the feeding ratio.

For example, we have two ratios, 1:2:2 and 1:6:6. Which one would be a higher feeding ratio? The answer is 1:6:6 because it has a higher ratio of flour and water to “seed” starter.

• Low Ratio: Less food relative to the amount of starter. Examples: 1:1:1, 1:2:2
• High Ratio: More food relative to the amount of starter. Examples: 1:4:4, 1:5:5

Adjusting the ratio allows bakers to control the activity level and readiness of the starter.

Temperature's Role in Fermentation

Temperature also plays a vital role in the fermentation rate of your sourdough starter. Warmer temperatures will speed up fermentation, while cooler temperatures will slow it down. For our purposes of comparing ratios in this article, we are comparing starters kept at the same temperature. Using a temperature-controlled device, like the Sourdough Home, can help with starter maintenance by providing a consistent temperature ensuring your starter behaves more predictably, and giving you more control over your starter's fermentation rate.

What is the Best Feeding Ratio to Use for Sourdough Starter?

There is no “one best feeding ratio”; instead, the best one to choose is the one that aligns with your baking schedule while promoting a healthy, active starter. The primary consideration is deciding how quickly you want your starter to ripen.

I Want My Starter to Ripen on a Shorter Timeline

Choose a lower ratio (e.g., 1:1:1 or 1:2:2): With lower ratios, the microbes receive a smaller proportion of food. As a result, they will use up the available food source more quickly and ripen faster than a higher ratio. This can be useful if you need to use your starter ready on a shorter timeline. For example, a 1:1:1 ratio may ripen in 4 to 5 hours. With a lower ratio, you will need to feed your starter more frequently.

I Want My Starter to Ripen on a Longer Timeline

Choose a higher ratio (e.g., 1:4:4 and above): With higher ratios, the microbes receive a larger proportion of food, and it will take longer for your starter to ripen. This can be useful if you want to feed your starter at night and have it ready in the morning. For example, a 1:8:8 ratio may need 10 hours to ripen. A higher ratio will allow you to extend the time between feedings which can make maintenance easier.

Sourdough starter fed with a low seed ratio will ripen faster than one fed with a high seed ratio. As you can see in the video, the starter with the highest ration (1:10:10) took the longest to ripen. 

Seed ratio is an important factor to consider when planning the timeline of your baking schedule. 

Our Recommendation

Mastering the art of sourdough starter maintenance through understanding feeding ratios is crucial for any baker. By understanding and adjusting the seed ratio according to your needs, you can ensure that your starter remains vigorous and ready for baking. Whether you need a quick-ripening starter or prefer a low-maintenance routine, selecting the right feeding ratio will help you achieve the best results in your sourdough baking journey.