Deep Dive
The Master's Ratio: A Deep Dive into Baker's Maths and Recipe Scaling
In the world of artisanal bread baking, consistency is what elevates a baker from one-hit wonder to master craftsman. While home baking often relies on relatively imprecise measurements such as cups and 'dashes', professional baking (and serious hobbyist baking) is based on a specialised mathematical system known as Baker's Maths (or Baker's Percentages).
Baker's maths is the lingua franca of professional baking. Once you can read a formula expressed in percentages, you can compare two recipes at a glance, predict roughly how a dough will behave before you mix it, and scale any loaf up or down without breaking the balance. It is the difference between following a recipe and understanding bread.
The Philosophy of Precision: Weight vs. Volume
The first challenge for any aspiring baker is to stop using a measuring cup. In bread baking, volumes are notoriously unreliable because ingredients can vary significantly in density. For example, a cup of flour can weigh anywhere between 120 and 150 grams, depending on how tightly it was packed into the container, the ambient humidity and how long it has been sitting on the shelf.
By contrast, 100 grams of flour is always 100 grams. Using a digital scale to measure in grams, the unit preferred by professionals, eliminates the guesswork that can lead to gummy crumbs or dense loaves. Baker's maths is entirely based on weight, so whether you bake one loaf at home or 10,000 in a commercial facility, the ratios will be the same.
The 100% Rule: Flour as the Anchor
The central concept of baker's maths is that the total weight of the flour is always represented as 100%. Each additional ingredient, such as water, salt, yeast, starter and inclusions, is expressed as a percentage of the total flour weight.
This is where many beginners get confused. In standard ('true') percentages, the total of all the components of a mixture must equal 100%. However, in baker's maths, the total percentage of a dough formula will always exceed 100% because everything is compared relative to the flour.
| Ingredient | Weight | Baker's % | True % |
|---|---|---|---|
| Bread flour | 500 g | 100% | 56.8% |
| Water | 350 g | 70% | 39.8% |
| Salt | 10 g | 2% | 1.1% |
| Starter | 20 g | 4% | 2.3% |
| Total | 880 g | 176% | 100% |
Setting the flour at 100% enables bakers to instantly understand the character of a formula at a glance. A salt ratio of 2% tells you the bread will be well seasoned. Similarly, an 80% water ratio indicates that the dough will be wet and extensible, with an open crumb.
Step-by-Step: Converting a Recipe
- Identify the total flour weight. Add every flour in the recipe (bread + whole wheat + rye, etc.).
- Divide each ingredient by the total flour to get a ratio.
- Multiply by 100 to convert the ratio into a percentage.
The core formula
Baker's % = (Ingredient weight ÷ Total flour weight) × 100
Example
750 g water ÷ 1000 g flour = 0.75 × 100 = 75% hydration
The Hydration Spectrum: Designing Your Crumb
The hydration level is one of the most visible metrics on every recipe card. In baker's maths, hydration refers specifically to the water-to-flour ratio, and it is the single number that tells you most about how a dough will behave:
- Low (50–60%): stiff doughs for bagels and pretzels. Easy to shape, dense and tight crumb.
- Medium (60–75%): sandwich loaves, batards. Workable, soft, uniform crumb.
- High (75–85%): country sourdough, levain. Sticky, requires stretch-and-folds, irregular alveoli.
- Extreme (85–110%+): ciabatta, focaccia, Pan de Cristal. Behaves like batter, translucent crumb walls.
Scaling: One Factor, Every Stage
One of the greatest benefits of baker's maths is the ability to scale a recipe up or down without breaking the dough's balance. The procedure is the same whether you are scaling a single dough or a multi-stage formula with a levain, a soaker and a main dough:
- Sum the percentages (e.g. 100% flour + 75% water + 2% salt + 20% starter = 197%).
- Divide your desired total weight by the sum (as a decimal). That gives you the new flour weight.
- Multiply that new flour weight by each ingredient's percentage to get the new ingredient weights.
Scale a formula to a target dough weight
Enter the percentages of your formula and the dough weight you want; you'll get the gram weights.
Most serious bread formulas are not single doughs. A levain feeds the main dough. A soaker hydrates seeds before mixing. A scald or tangzhong gelatinises part of the flour ahead of time. Each of these is a sub-recipe with its own ingredient list and its own internal ratios, and when you scale the final loaf, every one of them has to scale in lock-step or the formula falls apart.
Loafly Day represents a recipe as an ordered list of sub-recipes (levain, soaker, main dough, and so on) and stores every ingredient as a gram weight. Scaling is then a single arithmetic operation applied uniformly across all of them:
Because the same factor is applied to every ingredient in every sub-recipe, the percentages within each stage (levain hydration, soaker ratio, main dough hydration) stay identical. Doubling the loaf doubles the levain, the soaker, and the main dough simultaneously; halving it halves them. The ratios are what define the bread; the scale factor only decides how much of it you make.
This is also what makes forking work. When you fork a 900 g batard formula and rescale it to a pair of 1.6 kg miches, the levain quietly grows to match. You don't have to recalculate it by hand, and you can't accidentally end up with too little leaven for the new flour mass.
Advanced Sourdough: Accounting for the Levain
For advanced sourdough bakers, a simple "20% starter" line is often not precise enough. Because a sourdough starter consists of both flour and water, it shifts the true hydration of your dough. Professional formulas often disclose the "overall" baker's percentage that accounts for the hidden flour and water inside the levain.
Full-disclosure hydration
True hydration = (water in dough + water in starter) ÷ (flour in dough + flour in starter) × 100
Why your dough feels wetter than the recipe says
Add the levain. The "main dough" hydration is just one part of the picture.
Difference: +3%. That's the gap between what the recipe says and what your hands are actually feeling.
Inclusions: Adding Depth with Precision
Inclusions like seeds, nuts, cheese and dried fruit are also expressed as a percentage of the flour weight, so they don't overpower the structure of the loaf. Typical baker's percentages:
| Inclusion | Recommended | Effect |
|---|---|---|
| Seeds (sesame, poppy, flax) | 5–15% | Minimal structural impact |
| Nuts & dried fruit | 20–40% | May require slightly higher hydration |
| Cheese (cheddar, gouda) | 15–25% | Adds fat, softens crumb |
| Fats (butter, oil) | 2–15% | Increases tenderness and shelf life |
When adding "thirsty" inclusions like bran or certain seeds, bakers often increase hydration by 2–5% to compensate for what the inclusions absorb during the bake.
Troubleshooting with Baker's Maths
One of the most powerful uses of this system is diagnostic. Instead of guessing why a loaf failed, analyse the percentages to find the culprit:
- Dough won't hold its shape: is hydration too high for the protein content of your flour?
- Bread tastes flat: is the salt below the standard 1.8–2.2% range?
- Loaf over-proofs too fast: is the levain percentage too high for your kitchen temperature?
- Gummy crumb: was the hydration too high, or did you cut before the internal temperature reached 96°C / 205°F?
If you remember nothing else from this guide: flour is 100%, everything else is expressed relative to it, and the two numbers that tell you most about an unfamiliar recipe at a glance are the salt ratio (typically 1.8–2.2%) and the hydration (typically 60–85% for sourdough).