Sourdough Ratio Calculator
Calculate perfect sourdough bread ratios including starter percentage (inoculation), hydration, and salt levels. Enter your flour weight and desired percentages to get exact gram measurements for starter, water, and salt — ensuring consistent, repeatable sourdough bakes every time.
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What is a Sourdough Ratio?
Sourdough baking relies on precise ratios between four core ingredients: flour, water, sourdough starter (levain), and salt. The starter inoculation percentage (typically 15-25% of flour weight) determines fermentation speed and flavor development. Higher percentages ferment faster but produce milder flavor. Lower percentages ferment slower, developing more complex tang. Getting these ratios right is the difference between a spectacular loaf and a dense, flat disappointment.
Unlike commercial yeast baking where timing is predictable, sourdough timing depends on starter strength, inoculation percentage, ambient temperature, and flour type. This calculator helps you control the one variable you can measure precisely — the ingredient ratios. Combined with temperature control and visual fermentation assessment, precise ratios form the foundation of consistent sourdough baking.
使用される計算公式・方程式
この計算ツールは5つの主要な公式を使用しています：
1 Starter Amount ▼
For 20% starter with 500g flour: Starter = 500 × 0.20 = 100g.
2 Adjusted Water (accounting for starter) ▼
Assuming 100% hydration starter: half is flour, half water. Subtract the starter's water contribution.
3 Total Dough Weight ▼
500g flour + 350g water + 100g starter + 10g salt = 960g total dough.
Explore all calculation options on the 比率計算ツール home page.
比率計算ツールの使い方
この比率計算ツールは、以下の3ステップで簡単にご利用いただけます：
数値を入力
入力欄に既知の比率の値を入力します。求めたい未知数の入力欄は空欄のままにしておきます。
モードを選択
比率モード（解く、簡素化、スケーリング）を選択します。各モードで異なる計算式が適用されます。
結果を確認
計算するボタンを押します。結果画面に答えと、視覚的な比率バー、円グラフ、詳細なステップバイステップの解決プロセスが表示されます。
実例問題と段階的な解説
本比率計算ツールを使って、以下の3つの例題をステップバイステップで解決するプロセスです：
入力 1 Standard country loaf: 500g flour, 20% starter, 72% hydration
入力 2 High-hydration sourdough: 80% hydration, 25% starter
入力 3 Starter feeding ratio: 1:5:5
よくある質問 (FAQ)
What is the best sourdough starter ratio for bread? ▼
Most recipes use 15-25% inoculation (starter as a percentage of total flour weight). 20% is a reliable starting point. Higher percentages (25-30%) produce faster fermentation and milder flavor. Lower percentages (10-15%) ferment slower with more complex tang. Adjust based on your schedule and temperature.
How do I calculate sourdough hydration with starter? ▼
Add the water from your starter to the recipe water, and the flour from your starter to the recipe flour. For a 100% hydration starter: water contribution = starter weight ÷ 2, flour contribution = starter weight ÷ 2. Then calculate: total hydration = total water ÷ total flour × 100.
What hydration should sourdough bread be? ▼
Most sourdough bread recipes fall between 68-78% hydration. Beginners should start at 68-70% (manageable, less sticky). Intermediate bakers can try 72-75% (better open crumb). Advanced bakers work at 78-82% for very open, rustic crumbs. The right hydration depends on your flour and skill level.
How much salt should I use in sourdough? ▼
Standard sourdough uses 1.8-2.2% salt relative to total flour weight. For 500g flour, that is 9-11g salt. 2% (10g per 500g flour) is the most common recommendation. Fine sea salt dissolves fastest. Reduce to 1.5% for low-sodium diets, understanding fermentation will be slightly faster.
What is inoculation percentage in sourdough? ▼
Inoculation percentage is the weight of starter used relative to the total flour weight: (Starter Weight ÷ Total Flour Weight) × 100. A recipe with 100g starter and 500g flour has 20% inoculation. This controls fermentation speed — higher inoculation = faster rise.
How do I adjust sourdough ratios for cold weather? ▼
In cold environments (below 68°F/20°C), increase inoculation to 25-30%, use warmer water (85-90°F/29-32°C), and expect longer fermentation times. Alternatively, use a proofing box or warm oven to maintain consistent temperature.
Can I use a stiff starter instead of a liquid starter? ▼
Yes, but adjust your recipe calculations. A 50% hydration starter contributes more flour and less water than a 100% hydration starter. For 100g of 50% starter: 66.7g flour + 33.3g water. Specify your starter hydration in the calculator for accurate results.
What is the difference between levain and starter? ▼
The starter (mother) is your ongoing culture, fed and maintained continuously. Levain is a portion of starter that is specifically fed and built for a recipe, often at a different hydration or with different flour. Think of the starter as the permanent culture and the levain as the recipe-specific portion built from it.
How do I scale a sourdough recipe for more loaves? ▼
Multiply all ingredients by the number of loaves. A recipe for one 900g loaf scaled to 3 loaves: multiply flour, water, starter, and salt by 3. The percentages remain identical — only the total weights change. Account for slightly faster bulk fermentation in larger dough masses (more thermal mass).
Why is my sourdough too sour? ▼
Excessive sourness usually results from over-fermentation. Reduce inoculation (try 10-12%), shorten bulk fermentation time, use cooler water, or reduce the overnight cold retard period. Higher ratios of white flour to whole grain also reduce sourness. Conversely, for more tang, do the opposite.