Summer Sourdough Crushed Ice & Water Temp Chart for a Hot 86 Degree (86°F / 30°C) Kitchen — Hand Mixing (75°F Target DDT)
4-factor Desired Dough Temperature (DDT) and 80 cal/g latent heat crushed-ice calculation for hitting 75°F dough in a hot 86°F room.
Four inputs decide the temperature of your water: the 75°F target dough, a 86 deg F room, 86 deg F flour, 86 deg F levain, and +2°F from hand mixing (75°f target ddt). Solve 4 × 75°F − (86 + 86 + 86 + 2) and you land on 40°F (4.4°C) of mix water in this 86 deg F (30°C) kitchen. The faucet supplies 78°F and the dough needs 40°F, so ice is the only route: weigh 70g of crushed ice and 280g of 78°F water for the 350g batch, exploiting 80 cal per gram of phase change.
- Required Water Temp
- 40°F (4.4°C)To hit 75°F DDT in 86°F room
- 350g Batch Ice Split
- 70g Ice / 280g WBased on 78°F tap water & 80 cal/g latent heat
- Mixer Friction Factor
- +2°FHand Mixing
- Target Final Dough Temp
- 75°F (23.9°C)Locks fermentation clock & protease rate
Water Temperature Solver: 86°F (30°C) Room, Hand Mixing (75°F Target DDT) (+2°F)
Read the ice column as a direct instruction: weigh that much crushed ice and make up the balance with 78°F tap water.
| Total Water | Calculated Temp | Ice Quantity | Tap Water Quantity | Dough Temp Target |
|---|---|---|---|---|
| Line 350g [350g Ref] | required 40°F (4.4°C) | weigh 70g ice | measure 280g liquid | expect 75°F dough |
| Line 400g 100g Lighter | required 40°F (4.4°C) | weigh 80g ice | measure 320g liquid | expect 75°F dough |
| Line 300g 100g Heavier | required 40°F (4.4°C) | weigh 60g ice | measure 240g liquid | expect 75°F dough |
| Line 500g Half Batch | required 40°F (4.4°C) | weigh 100g ice | measure 400g liquid | expect 75°F dough |
| Line 250g Large Batch | required 40°F (4.4°C) | weigh 50g ice | measure 200g liquid | expect 75°F dough |
Real-Time Dough & Starter Scaling Sandbox
Scale this What Water Temp for Sourdough in a 8 specification up or down on your digital scale with zero hydration drift.
Baking Sourdough in a Hot 86°F Room: Why You Need 40°F Water (70g Ice)
Latent heat of fusion is why the cooling arithmetic is not linear. Replacing 70g of the 350g of water with crushed ice removes not merely 70g × 1 cal/g of sensible heat, but 70g × 80 cal/g of phase-change heat, which is what allows a 30°C (30°C) room to be cooled into a 75°F dough.
Friction factors are equipment-specific. The +2°F used for hand mixing (75°f target ddt) is a lumped parameter covering the steel bowl, ambient convection, hydration exotherm and shear work, and it changes if you switch from a spiral hook to a paddle.
Thermal Control Protocol for Hand Mixing (75°F Target DDT) in a 86°F Room
- Account for the Friction First: Hand Mixing adds +2°F, so subtract it from your target before you calculate the water temperature — that single step is what distinguishes a 75°F dough from a warm one.
- Solve the 4-Factor Equation: 4 × 75°F − (86 + 86 + 86 + 2) = 40°F of mix water for this 86°F (30°C) room.
- Execute the Ice Swap: Replace 70g of the 350g with finely crushed ice and keep 280g of 78°F tap water, melting the ice fully first.
- Probe the Finished Dough: The reading should be 75°F ± 1°F; anything else means one of the three probed ingredients was off.
Diagnostic Answers: What Water Temp for Sourdough in a 86°F (30°
Will the dough temperature change if I scale the recipe?
No. The 4-factor equation is a temperature balance, not a mass balance, so doubling the flour and water keeps the same 40°F target — but you must double the ice too, from 70g to 140g.
How accurate is the 40°F figure in practice?
Within about 1°F, provided the four inputs really are 86°F room, 86°F flour, 86°F levain and +2°F friction. Probe the finished dough to confirm and adjust your next bake.
How much ice do I add to 350g of bread water in a 86°F room (Hand Mixing (75°F Target DDT))?
Replace 70g of water with finely crushed ice and use 280g of 78°F tap water to hit 75°F DDT.