Sourdough Water Temperature & Fermentation Calculator
Calculate water temperature and estimate fermentation time based on your dough conditions.
🌡️ Step 1: Target Water Temp Calculator
⏱️ Step 2: Bulk Fermentation Predictor
After mixing, measure the actual temp of your dough (FDT) to get an estimated fermentation time.
How to Use This Tool
Just follow these simple steps to get your ideal water temperature and fermentation estimate.
1. Enter Your Temperatures
Measure your room temperature and flour temperature.
(Flour is usually the same as room temperature.)
2. Choose Your Mixing Method
Select whether you're mixing by hand or using a stand mixer. Mixer friction will slightly increase dough temperature.
3. Get Your Results
We’ll calculate your ideal water temperature. After mixing, enter your final dough temperature to estimate bulk fermentation time.
Why This Matters
Fermentation is a temperature game: The wild yeast and bacteria in your sourdough starter are happiest between 75°F and 78°F. If your dough is too cold (under 70°F), it gets sluggish, resulting in a dense, flat loaf. If it's too hot, the bacteria go into overdrive—making your dough overly sour, sticky, and weak.
Water is your secret weapon: You can't easily change the temperature of your kitchen or your bag of flour. That makes water your only control dial. By using warm water on a chilly winter day, or ice water during a summer heatwave, you balance out the environment so your dough hits that perfect target temperature.
Watch the dough, not the clock: Our estimated time gives you a "golden window." As that time approaches, look at your dough. Has it grown by 40% to 50%? Is the surface smooth and domed with scattered bubbles? Does it jiggle like gelatin when you gently shake the bowl? If so, fermentation is done and it's time to prep it for your cast-iron pan!