Calculator
Water temperature calculator
You can’t change how cold your flour or kitchen is on bake day — but you can change the water. Set your target dough temperature, enter what you’ve got, and this gives you the exact water temperature to land it. The single biggest thing you can do to make your fermentation schedule predictable.
- Use water at
- 88°F
- What that means
- Room-temperature to cool tap water
How the math works
Four things average into the dough’s temperature — flour, room, starter, and water — so the four must sum to four times your target. The water makes up the difference, minus any heat the mixing adds:
water = (target × 4) − flour − room − starter − friction.
Friction is ~0 for hand-mixing or no-knead sourdough and roughly 6–10°F for a stand mixer. Source: standard baker’s temperature math (Reinhart, King Arthur, Modernist Bread).
Why dough temperature is the whole game
Dough temperature is the master control on fermentation speed — a few degrees decides whether bulk takes four hours or seven. Most recipes give you a timeline assuming a 76°F dough; if yours comes out at 70°F because the flour and water were cold, every timing is suddenly wrong. Hitting a consistent dough temperature is what makes the schedule repeatable.
- Cold dough = slow, unpredictable
A dough that lands at 68–70°F ferments far slower than the recipe expects. You wait, second-guess, and often under-proof.
- Warm dough = fast, easy to over-do
Above ~80°F the ferment races; bulk can finish before you're ready and the dough turns slack and sour.
See how every kitchen temperature shifts bulk + proof time →
The full baking schedule — where dough temperature sets the clock →
You can only hit a number you can read
The calculator needs your flour, room and starter temperatures — and you confirm the water by reading it. An instant-read thermometer turns dough temperature from a guess into a number you control.
Instant-read thermometerRead the flour, the water, and the finished dough in seconds — the one tool that makes this calculator real instead of theoretical.
Compare thermometers on Amazon → 🎧 The science of the bakeMaurizio Leo’s The Perfect Loaf and Ken Forkish’s Flour Water Salt Yeast explain why temperature rules fermentation — both on Audible with a free trial.
Start a free Audible trial → As an Amazon Associate, SourdoughHydration earns from qualifying purchases at no extra cost to you. More on how this is funded.
Common questions
What is desired dough temperature (DDT)?
DDT is the temperature you want your dough to be right after mixing, because that temperature sets how fast it ferments. For sourdough, most bakers aim for about 75–78°F (24–25.5°C). The water is the ingredient you adjust to hit it — warmer water if your kitchen and flour are cold, cooler water if everything is warm.
What is a good target dough temperature for sourdough?
Around 76–78°F (24–25.5°C) is the common sweet spot — warm enough for a lively, predictable bulk ferment without rushing it. Run cooler (72–74°F) for a slower ferment and more flavour development; warmer (78–80°F) when you want to move faster. Pick the target, then let the calculator tell you the water.
How do I measure water temperature?
An instant-read kitchen thermometer is the simplest way — read the flour, the room, and the starter, plug them in, then adjust the tap water until it reads the number the calculator gives. With a little practice you can hit it by feel, but a thermometer removes the guesswork, especially in winter when tap water runs cold.
Does mixing friction matter for sourdough?
For hand-mixing or no-knead sourdough, friction adds almost nothing — leave it at 0. A stand mixer working the dough adds heat, typically around 6–10°F, so add that as the friction factor if you machine-mix. When in doubt, start at 0; it's easier to warm a cool dough than to cool a hot one.