Baking sourdough bread is a deeply rewarding craft that connects bakers to an ancient tradition of natural leavening. At the heart of this craft is the sourdough starter—a living culture of wild yeast and bacteria that must be fed and cared for like a pet. Managing your starter's feeding schedule and ratios is the key to developing a strong, active culture that will produce beautiful, airy loaves of bread. Our Sourdough Starter Calculator is an essential tool for bakers of all levels, designed to simplify the daily maintenance of their starter by calculating the precise amounts of flour and water needed for any given feeding ratio.
How to Use the Sourdough Starter Calculator
Calculating your starter's daily meal is a simple process:
- Enter Starter Amount: Input the amount of starter you plan to keep (in grams) after discarding the rest.
- Set Your Feeding Ratio: Enter your desired feeding ratio of Starter:Flour:Water. For example, a 1:2:2 ratio is a common choice for a twice-daily feeding.
- Calculate Your Feeding: Click the "Calculate Feeding" button to see the exact weight of flour and water (in grams) you need to add to your starter.
The Science of a Sourdough Starter
A sourdough starter is a symbiotic culture of wild yeasts and lactic acid bacteria that are naturally present on the flour and in the air. When you mix flour and water and leave it at room temperature, these microorganisms begin to multiply.
- The yeasts are responsible for producing carbon dioxide gas, which gets trapped in the dough's gluten network and causes the bread to rise.
- The lactic acid bacteria produce lactic and acetic acids, which give sourdough bread its characteristic tangy flavor and also help to preserve it naturally.
"Feeding" your starter with fresh flour and water provides the food these microorganisms need to stay active and healthy. The "discard" process is necessary to manage the size of your starter and to keep the population of yeast and bacteria in a healthy balance.
Understanding Feeding Ratios
The feeding ratio is expressed as three numbers representing the proportion of Starter : Flour : Water by weight. The ratio you choose has a significant impact on your starter's behavior and your baking schedule.
- A 1:1:1 Ratio: This means you feed your starter with equal weights of starter, flour, and water (e.g., 50g starter, 50g flour, 50g water). This provides a large population of microorganisms with a relatively small amount of new food, leading to a very fast and vigorous fermentation. A starter fed at this ratio will often peak (be ready to use) in just 4-6 hours, making it ideal for bakers who want to bake frequently or on the same day.
- A Higher Ratio (e.g., 1:2:2, 1:5:5, or even 1:10:10): In this case, you are giving a smaller amount of starter a much larger meal. This slows down the fermentation process significantly. A starter fed at a 1:5:5 ratio might take 12-16 hours to peak. This is perfect for bakers who only want to feed their starter once a day, or who want to time their starter to be perfectly ripe in the morning after an overnight feeding.
Experimenting with different ratios allows you to manipulate the fermentation timeline to perfectly fit your personal schedule.
What is "Hydration"?
The term hydration in sourdough refers to the amount of water relative to the amount of flour. In a starter fed at a 1:1:1 ratio, the hydration is 100% (equal parts flour and water). In a starter fed at a 1:2:2 ratio, the hydration is also 100%. A "stiffer" starter might be fed at a 1:2:1 ratio, resulting in a 50% hydration. A stiffer starter ferments more slowly and develops a more acetic (vinegar-like) flavor, while a 100% hydration starter ferments faster and produces a more lactic (yogurt-like) flavor.
Frequently Asked Questions
Why do I have to discard part of my starter?
If you were to feed your entire starter every day without discarding, it would grow exponentially, and you would quickly have an unmanageable amount of starter requiring huge amounts of flour. The discard process keeps the starter at a manageable size and, more importantly, refreshes the culture, ensuring the yeast and bacteria have plenty of fresh food to consume, which keeps them healthy and active.
How do I know when my starter is "ripe" and ready to use?
A ripe starter will have several signs. It will have roughly doubled or tripled in volume from when you fed it. It will be full of bubbles, both large and small. It will have a pleasant, slightly acidic, yeasty aroma. The ultimate test is the "float test": drop a small spoonful of the starter into a glass of water. If it floats, it is full of gas and ready to leaven your bread.
What kind of flour should I use to feed my starter?
You can use a variety of flours. Many people maintain their starter with unbleached all-purpose or bread flour. It's also a common practice to include a small amount of whole wheat or rye flour in the feeding. These whole-grain flours contain more nutrients and microorganisms, which can help to boost your starter's activity and contribute to a more complex flavor in your final bread.
What if I don't want to bake every day?
If you don't plan on baking frequently, you can store your starter in the refrigerator. The cold temperature will dramatically slow down the fermentation process. You will only need to take it out and feed it about once a week to keep it healthy. When you are ready to bake, take it out of the fridge and give it two or three regular feedings at room temperature to get it back to full strength and activity.