Sourdough Starter Ratio Calculator
Mastering the Sourdough Starter Ratio
Managing a sourdough starter is a delicate balance of biology and mathematics. Whether you are preparing for a weekend bake or maintaining your "mother" culture in the fridge, understanding how to calculate feeding ratios is essential for consistent bread. The Sourdough Starter Ratio Calculator simplifies this process, ensuring you have exactly the amount of levain you need without excessive waste.
What Do Sourdough Feeding Ratios Mean?
A sourdough ratio is expressed as Starter : Flour : Water. For example, a 1:2:2 ratio means that for every 1 part of existing starter, you add 2 parts of flour and 2 parts of water by weight.
- 1:1:1 Ratio: Often used for daily maintenance. It ferments quickly because the concentration of yeast/bacteria is high relative to the new "food."
- 1:2:2 Ratio: A common ratio for building a levain for a recipe. It takes longer to peak than a 1:1:1 feed.
- 1:5:5 Ratio: Used when you want to extend the fermentation time (e.g., feeding overnight for a morning mix) or to reduce the acidity of a very sour starter.
How to Calculate Your Starter Feed
To calculate the weights manually, you first sum the parts of your ratio. If you want 300g of total starter at a 1:2:2 ratio, you have 5 total parts (1+2+2). Divide 300 by 5 to get 60g per part. Therefore, you need 60g starter, 120g flour, and 120g water.
Example: Preparing Levain for a Recipe
Imagine your recipe calls for 150g of active sourdough starter. You should always make slightly more to account for what sticks to the jar. Let's aim for 160g at a 1:3:3 ratio:
- Total Parts: 1 + 3 + 3 = 7 parts.
- Weight per part: 160g / 7 ≈ 22.8g.
- Starter: 22.8g.
- Flour: 68.4g.
- Water: 68.4g.
Tips for Successful Starter Maintenance
1. Temperature Matters
Ratios determine the "food" availability, but temperature determines the speed of consumption. A 1:1:1 starter at 80°F (27°C) will peak much faster than the same starter at 65°F (18°C).
2. Flour Choice
Whole grain flours (Rye, Whole Wheat) ferment faster than white bread flour or All-Purpose flour because they contain more nutrients and minerals that stimulate yeast activity.
3. Consistency is Key
Using a digital scale is non-negotiable in sourdough baking. Volume measurements (cups/spoons) are too inaccurate for starters, as the aeration of the culture significantly changes its volume but not its mass.
Frequently Asked Questions
What is 100% hydration? 100% hydration means the weight of the water equals the weight of the flour in the feed. Most common sourdough ratios (1:1:1, 1:2:2) result in 100% hydration starters.
When is my starter ready to use? Most starters are ready when they have doubled in size and pass the "float test" (a small dollop floats in water), though the float test is not always reliable for rye starters.