Summer Sourdough Crushed Ice & Water Temp Chart for a Hot 80 Degree (80°F / 27°C) Kitchen — Hand Mixing (78°F Target DDT)
4-factor Desired Dough Temperature (DDT) and 80 cal/g latent heat crushed-ice calculation for hitting 78°F dough in a hot 80°F room.
Heat flows in two directions in a 26.7°C (26.7°C) kitchen: heat flows from the 26.7°C flour and levain into the dough, and hand mixing (78°f target ddt) adds +2°F of its own. To land the finished dough on 78°F, the 339g of liquid water must enter at 70°F (21.1°C). Cooling from 76°F tap water down to 70°F means melting 11g of ice into the 350g batch and leaving 339g of liquid water; each gram of ice absorbs 80 cal on melting alone.
- Required Water Temp
- 70°F (21.1°C)To hit 78°F DDT in 80°F room
- 350g Batch Ice Split
- 11g Ice / 339g WBased on 76°F tap water & 80 cal/g latent heat
- Mixer Friction Factor
- +2°FHand Mixing
- Target Final Dough Temp
- 78°F (25.6°C)Locks fermentation clock & protease rate
Water Temperature Solver: 80°F (26.7°C) Room, Hand Mixing (78°F Target DDT) (+2°F)
Assumes room, flour and levain are all at 80°F (26.7°C) — probe them before trusting the numbers.
| Recipe Water Weight | Required Mix Temp | Crushed Ice Weight | Tap Water (@ 76°F) | Achieved Dough Temp |
|---|---|---|---|---|
| 250g water (80°F / +2°F) [Baseline] | 70°F (21.1°C) | 8g crushed ice | 242g tap water (@ 76°F) | 78°F (25.6°C) final dough |
| 400g water (80°F / +2°F) Down 50g | 70°F (21.1°C) | 13g crushed ice | 387g tap water (@ 76°F) | 78°F (25.6°C) final dough |
| 350g water (80°F / +2°F) Up 50g | 70°F (21.1°C) | 11g crushed ice | 339g tap water (@ 76°F) | 78°F (25.6°C) final dough |
| 300g water (80°F / +2°F) Down 100g | 70°F (21.1°C) | 10g crushed ice | 290g tap water (@ 76°F) | 78°F (25.6°C) final dough |
| 500g water (80°F / +2°F) Up 150g | 70°F (21.1°C) | 16g crushed ice | 484g tap water (@ 76°F) | 78°F (25.6°C) final dough |
On-Bench Hydration & Fermentation Adjuster
Modify base flour mass, levain inoculation, or ambient kitchen temperature below to recalculate from this 70°F (21.1°C) baseline.
Baking Sourdough in a Hot 80°F Room: Why You Need 70°F Water (11g Ice)
Levain temperature is the silent variable in this equation. If the 80 deg F (26.7°C) kitchen assumption holds for the room and the flour but the levain actually sits two degrees cooler, the finished dough will miss the 78°F target by about half a degree, and in a hot month that is enough to ferment the dough noticeably faster than planned.
Ice quantity and water quantity are not interchangeable views of the same thing. 11g of crushed ice is the solid portion; the 339g of tap water that accompanies it is what actually hydrates the flour. Both numbers must be weighed.
Thermal Control Protocol for Hand Mixing (78°F Target DDT) in a 80°F Room
- Measure the Room First: Confirm the kitchen really is 80°F (26.7°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 80°F before mixing. Cold flour is the most common reason a 78°F target is missed in a 80°F (26.7°C) kitchen.
- Combine 11g Crushed Ice with 339g Tap Water: Mix the ice into the 76°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 78°F (±1°F) given the +2°F friction allowance.
Common Scaling & Troubleshooting Questions (70°F (21.1°C))
How much colder is the water than the room in this 80°F (26.7 Celsius) kitchen?
10°F below the room temperature of 80°F. That gap is the entire thermal load that 2°F of hand mixing (78°f target ddt) friction and 80°F ingredients impose on the mix water.
Can I mix the ice directly into the flour?
Yes, and it is often the better technique. Mixing 11g of crushed ice into the 339g of water and flour together chills the mass faster than adding cold water to warm flour, and the 80 cal/g phase change is fully captured.
What is the DDT formula for a 80°F kitchen using Hand Mixing (78°F Target DDT)?
Target water temperature = (4 × 78°F) − (80°F room + 80°F flour + 80°F levain + 2°F friction) = 70°F (21.1°C).