Summer Sourdough Crushed Ice & Water Temp Chart for a Hot 82 Degree (82°F / 28°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 82°F room.
Your mix water in a 27.8°C (27.8°C) room needs to sit at 52°F (11.1°C) to finish at 75°F, provided the flour, levain and room are all 27.8°C and hand mixing (75°f target ddt) contributes +2°F of mechanical heat. The arithmetic is 4 × 75°F − (82 + 82 + 82 + 2) = 52°F. Since the required 52°F sits below the 78°F coming from your tap, swap 48g of the 350g water for finely crushed ice — the 80 cal/g phase change does the cooling — and keep 302g of tap water alongside it.
- Required Water Temp
- 52°F (11.1°C)To hit 75°F DDT in 82°F room
- 350g Batch Ice Split
- 48g Ice / 302g 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
Desired Dough Temperature Grid at 82°F (27.8°C) Using Hand Mixing (75°F Target DDT)
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 |
|---|---|---|---|---|
| 250g recipe water — [Exact Target] | 52°F theoretical | 34g finely crushed | 216g from the tap at 78°F | final 75°F / 23.9°C |
| 400g recipe water — Alt Line A | 52°F theoretical | 55g finely crushed | 345g from the tap at 78°F | final 75°F / 23.9°C |
| 350g recipe water — Alt Line B | 52°F theoretical | 48g finely crushed | 302g from the tap at 78°F | final 75°F / 23.9°C |
| 300g recipe water — Alt Line C | 52°F theoretical | 41g finely crushed | 259g from the tap at 78°F | final 75°F / 23.9°C |
| 500g recipe water — Alt Line D | 52°F theoretical | 68g finely crushed | 432g from the tap at 78°F | final 75°F / 23.9°C |
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 82°F Room: Why You Need 52°F Water (48g Ice)
Latent heat of fusion is why the cooling arithmetic is not linear. Replacing 48g of the 350g of water with crushed ice removes not merely 48g × 1 cal/g of sensible heat, but 48g × 80 cal/g of phase-change heat, which is what allows a 82°F (27.8°C) room to be cooled into a 75°F dough.
Humidity shifts the effective room temperature slightly. A dry 27.8°C (82°F) day pulls moisture out of the dough surface and cools it a little, so a humid morning may want half a degree less cold water than the table suggests.
Thermal Control Protocol for Hand Mixing (75°F Target DDT) in a 82°F Room
- Measure the Room First: Confirm the kitchen really is 27.8°C (27.8°C) with a thermometer on the counter, not on the window, because radiant sun can read several degrees warmer than the working surface.
- Temper Flour and Levain: Bring both to 27.8°C before mixing. Cold flour is the most common reason a 75°F target is missed in a 27.8°C (27.8°C) kitchen.
- Combine 48g Crushed Ice with 302g Tap Water: Mix the ice into the 78°F water first and let it chill completely before it touches the flour.
- Mix and Check: After hand mixing, probe the dough — it should read 75°F (±1°F) given the +2°F friction allowance.
Diagnostic Answers: What Water Temp for Sourdough in a 82°F (28°
Why does my dough come out warmer than 75°F in a 82°F room?
Almost always the friction term. If you used 78°F tap water instead of 52°F, the 2°F that hand mixing (75°f target ddt) generates has nowhere to go, and the finished dough overshoots the target.
Do I need crushed ice or is a cold fridge fine?
Crushed ice, always. Chilling the bowl in the refrigerator removes heat far too slowly for a 350g batch; the 80 cal/g latent heat of fusion in 48g of crushed ice does the job in under a minute.
How much colder is the water than the room in this 82 deg F (27.8°C) kitchen?
30°F below the room temperature of 82 deg F. That gap is the entire thermal load that 2°F of hand mixing (75°f target ddt) friction and 82 deg F ingredients impose on the mix water.