Feed with intent · Free calculator
Starter Recipe Calculator
A starter is just a small recipe you repeat — and like any recipe, its hydration drives its behavior. This calculator builds a starter feeding from scratch: water, up to two flours, and other liquid ingredients (milk, juice, kefir and friends contribute their own water, and Sourjoe accounts for it).
Use it to design a stiffer starter for slower fermentation, a wetter one for a livelier culture, or simply to know what hydration the feeding you already do actually produces.
? Build a starter feeding recipe from scratch and see its hydration -- including any milk, juice, or other liquid ingredients.
| Parameter | Value |
|---|---|
| ? Water | |
| ? Flour 1 | |
| ? Flour 2 | |
| ? Other 1 | |
| ? Other 2 | |
| ? Recipe Hydration | -- |
Worked example
A standard Sourjoe maintenance feed is the 1:4:4 ratio: keep 25 g of your existing starter, add 100 g of warm water and 100 g of flour, and you're holding 225 g of starter at exactly 100% hydration. Enter that above — then try Sourjoe's own 50/50 split of whole wheat and all-purpose (50 g of each) and watch the hydration hold steady while the flour character changes.
Where it fits in the bake
Your starter is the engine behind everything in the Baker's Process, but it never goes into the dough directly — you'll scoop 15–25 g of it to build a leaven for each bake. Design the starter recipe here, then hand the numbers to the Leaven Calculator when it's time to bake.
Starter Recipe Calculator FAQ
What ratio should I feed my sourdough starter?
1:4:4 (starter : water : flour by weight) is a dependable maintenance feed for a refrigerated starter — 25 g starter, 100 g water, 100 g flour. Higher ratios like 1:5:5 take longer to peak; 1:1:1 peaks fast and suits reviving a sluggish jar.
What hydration should a starter be?
100% — equal weights of water and flour — is the standard, and it's what this calculator shows by default. Stiff starters (50–65%) favor yeast activity and milder flavor; liquid starters ferment faster and trend tangier.
Can I feed my starter two different flours?
Absolutely — the calculator has two flour inputs for exactly this. Sourjoe's house feed is 50/50 whole wheat and all-purpose: the whole wheat brings minerals and enzymes that keep the culture vigorous, the all-purpose keeps it predictable.
How much starter should I keep on hand?
225–450 g covers most home bakers. Any more just manufactures discard, since each bake only borrows 15–25 g as seed for a leaven. Size your feeds here so the jar stays useful, not wasteful.
Why does my starter smell like vinegar or alcohol?
It's hungry, not dead. The liquid layer (hooch) is ethanol from yeast that ran out of food, and the vinegar note is acetic acid — both normal after a stretch in the fridge. A feed or two at 1:4:4 brings it back. Fuzzy or colorful spots, though, mean mold: throw it out.
How do I convert my starter to a different hydration?
Decide the new water-to-flour ratio, then let the calculator recompute the feed — for a 75% starter, feed your usual 25 g seed with 75 g water and 100 g flour instead of 100/100. Two or three feeds at the new ratio and the culture settles into its new consistency.
Do I need to feed my starter if I’m not baking?
A refrigerated starter is remarkably patient — weekly feeding keeps it lively, and many bakers stretch to two or three weeks with nothing worse than extra tang and some hooch to pour off. One or two normal feeds bring even a neglected jar back to full vigor.
Want to know why this works? Every model and constant behind this calculator is explained, derived, and put to work in The Book of Sourjoe — the interactive book this calculator was built for.
These calculators are just the crust. Check out the Public Preview of the Sourjoe App — The Book of Sourjoe, recipes, and every baking tool in one place.
Questions? Comments? Send us a note at info@sourjoe.com.