BreadMath

Sourdough Math, Without the Spreadsheet

Sourdough baking is forgiving in the kitchen and unforgiving in the math. The difference between a dense brick and a beautifully open crumb often comes down to a few percentage points of hydration, an off-balance starter ratio, or a bulk ferment that ran half an hour long. BreadMath replaces the back-of-the-envelope calculations and the spreadsheet you keep meaning to update with one app that does the math live as you type.

Baker's Percentage, Explained

Baker's percentage is the universal language of bread recipes. Every ingredient is expressed as a percent of the total flour weight, with flour itself always equal to 100%. So a recipe with 1000 g flour, 750 g water, 20 g salt, and 200 g starter has 75% hydration, 2% salt, and 20% starter. The advantage is that you can scale a recipe up or down without losing the proportions — and you can compare two completely different recipes by their percentages instead of their gram totals.

Why Hydration Math Goes Wrong

The most common mistake in hydration math is forgetting the water inside the starter. A 200 g starter at 100% hydration is 100 g of flour and 100 g of water — which means it adds 100 g to your dough's total water and 100 g to its total flour. If you ignore that, your hydration percentage will be wrong by several points, which is the difference between a 75% country loaf and an 80% ciabatta. BreadMath asks for your starter's hydration and includes its water automatically.

Managing a Sourdough Starter

A healthy starter doubles in 4 to 8 hours after feeding at room temperature. The feeding ratio matters: 1:1:1 (equal parts starter, flour, and water by weight) is the standard, but 1:5:5 or even 1:10:10 is common for keeping a starter peaked longer in warm weather. Ambient temperature is the biggest variable — at 78°F a 1:1:1 starter peaks in about 4 hours; at 65°F it might take 8. BreadMath's starter manager tracks all of this and tells you when to feed next.

Bake Timeline Planning

A typical sourdough bake has eight stages: autolyse, mix, bulk ferment with stretch-and-folds, pre-shape, final shape, cold proof, score, and bake. Each one has a target time at a target temperature. If you start with the bake at 7 a.m. tomorrow morning and work backwards, you'll see that you need to shape at midnight tonight, which means bulk ferment started at 6 p.m., which means autolyse started at 5 p.m. BreadMath's bake timeline planner does this calculation in both directions and gives you a timer for each step.

Recipe Scaling for One Loaf or Six

You found a recipe online that makes one 900 g loaf, but your dutch oven holds 1500 g of dough. Or you've got a recipe that makes 2400 g of focaccia for a party but only need 1200 g. BreadMath's recipe scaler keeps every baker's percentage exact while changing the total dough weight or number of loaves — no pencil-and-paper, no rounding errors.

The Photo Bake Journal

The fastest way to improve as a baker is to keep notes on what you tried and how it turned out. BreadMath's photo journal lets you log every bake with a photo, a star rating, notes on what you did differently, and tags ('open crumb', 'overproofed', 'whole wheat', 'weekend bake'). Sort by top-rated to find your best loaves. Edit entries weeks later when you finally know whether that experiment was a keeper.

Built-In Recipes for Every Style

The free version includes three starter recipes — Basic Sourdough, Country Rye, and a yeasted Sandwich Loaf — so you can test the calculator on a real bake. Premium unlocks the full 16-recipe library: Whole Wheat Sourdough, Sourdough Baguette, Ciabatta, Focaccia, Multigrain, Honey Whole Wheat, Brioche, Sesame Bagels, Soft Pretzels, Neapolitan Pizza, Naan, Flour Tortillas, Cinnamon Rolls, and more. Every recipe shows full baker's percentages, real photos, and 5–7 step instructions with times and temperatures.

Privacy and Offline Use

BreadMath stores every recipe, journal entry, and photo locally on your device. No account, no cloud sync, no analytics. The app loads instantly — no spinners between screens — and works completely offline, which matters when you're elbow-deep in dough and don't want to chase wifi.

Phone and Tablet

On phones, BreadMath uses a clean single-column layout optimized for one-handed use. On tablets, the recipe library and journal switch to a 3-column grid so you can see more loaves at once, and tap targets are sized for flour-dusted fingers. Switch between metric grams and imperial ounces any time — both work.

Who Uses BreadMath?

BreadMath is built for the home baker who's outgrown the spreadsheet — someone who's been keeping a starter alive for a few months, has tried a few recipes, and wants to start dialing in their own. It's also useful for bakers running small farmers' market operations who need to scale recipes for production, and for cottage bakers tracking their best results over time. Whether you bake one loaf a week or six, BreadMath gives you the numbers you need to bake with confidence.