Summer Sourdough Crushed Ice & Water Temp Chart for a Hot 92 Degree (92°F / 33°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 92°F room.
If you mix with 78°F tap water in a 92 deg F (33.3°C) kitchen using hand mixing (78°f target ddt), the dough will land well above 78°F and ferment far too fast. The arithmetic 4 × 78°F − (92 + 92 + 92 + 2) gives the required 34°F (1.1°C) mix temperature instead. Your 78°F tap water is 44°F too warm for a 78°F dough, so 81g of crushed ice replaces that much of the 350g and 269g of tap water completes the mix.
- Required Water Temp
- 34°F (1.1°C)To hit 78°F DDT in 92°F room
- 350g Batch Ice Split
- 81g Ice / 269g WBased on 78°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: 92°F (33.3°C) Room, Hand Mixing (78°F Target DDT) (+2°F)
Assumes room, flour and levain are all at 92°F (33.3°C) — probe them before trusting the numbers.
| Recipe Water Weight | Required Mix Temp | Crushed Ice Weight | Tap Water (@ 78°F) | Achieved Dough Temp |
|---|---|---|---|---|
| [Primary]: 250g total water | mix at 34°F | substitute 58g ice | keep 192g warm water | friction +2°F absorbed |
| Small Mix: 400g total water | mix at 34°F | substitute 93g ice | keep 307g warm water | friction +2°F absorbed |
| Standard Mix: 350g total water | mix at 34°F | substitute 81g ice | keep 269g warm water | friction +2°F absorbed |
| Oversized Mix: 300g total water | mix at 34°F | substitute 69g ice | keep 231g warm water | friction +2°F absorbed |
| Double Mix: 500g total water | mix at 34°F | substitute 116g ice | keep 384g warm water | friction +2°F absorbed |
Custom Batch Recalculation Engine
Fine-tune starter hydration between 50% stiff and 125% liquid while keeping your desired dough temp (ddt) & ice solver ratios locked.
Baking Sourdough in a Hot 92°F Room: Why You Need 34°F Water (81g Ice)
Ice must be finely crushed. A 81g charge of coarse ice in a 33.3°C (33.3°C) kitchen melts unevenly through the mix, and the last shards can shock the wild yeast even though the bulk of the dough ends up at the correct 78°F.
Ice substitution scales with batch size, not with flour. The 81g of crushed ice quoted for 350g of water becomes proportionally larger for a bigger batch, because the same temperature deficit has to be removed from more mass.
Thermal Control Protocol for Hand Mixing (78°F Target DDT) in a 92°F Room
- Start the Night Before: In a 33.3°C (92°F) kitchen the flour will sit near room temperature overnight if you store it sealed, so re-probe it in the morning rather than trusting yesterday's reading.
- Prepare the Water Station: Get the 34°F (1.1°C) water ready before you open the flour bag — once the flour is wet the temperature negotiation is over.
- Blend Ice and Water: Stir 81g of crushed ice into 269g of 78°F tap water until the slush is uniform, then pour over the flour.
- Record and Repeat: Note the final probe reading alongside the 33.3°C (92°F) room temperature so the next bake is a copy rather than a calculation.
Technical Q&A: Summer Sourdough Crushed Ice & Water Temp Chart
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 34°F target — but you must double the ice too, from 81g to 162g.
How accurate is the 34°F figure in practice?
Within about 1°F, provided the four inputs really are 92°F room, 92°F flour, 92°F levain and +2°F friction. Probe the finished dough to confirm and adjust your next bake.
Why does my dough come out warmer than 78°F in a 92°F room?
Almost always the friction term. If you used 78°F tap water instead of 34°F, the 2°F that hand mixing (78°f target ddt) generates has nowhere to go, and the finished dough overshoots the target.