Summer Sourdough Crushed Ice & Water Temp Chart for a Hot 90 Degree (90°F / 32°C) Kitchen — High-Friction Planetary Mixer (74°F DDT)
4-factor Desired Dough Temperature (DDT) and 80 cal/g latent heat crushed-ice calculation for hitting 74°F dough in a hot 90°F room.
In this 90 deg F (32.2°C) room, high-friction planetary mixer (74°f ddt) adds +24°F of mechanical friction to a dough whose flour and levain are also 90 deg F. The 4-factor Desired Dough Temperature equation therefore calls for mix water at 2°F (-16.7°F) to deliver a 74°F (23.3°C) dough. There is no faucet setting that reaches 2°F here, so reach for ice: 140g finely crushed plus 210g of 78°F tap water brings the batch to 74°F through 80 cal/g of latent heat.
- Required Water Temp
- 2°F (-16.7°C)To hit 74°F DDT in 90°F room
- 350g Batch Ice Split
- 140g Ice / 210g WBased on 78°F tap water & 80 cal/g latent heat
- Mixer Friction Factor
- +24°FHigh-Friction Planetary Mixer
- Target Final Dough Temp
- 74°F (23.3°C)Locks fermentation clock & protease rate
Batch-Scaled Ice & Water Chart for a 90°F Kitchen (High-Friction Planetary Mixer (74°F DDT))
Each row re-solves the 4-factor equation at a different batch size; the 2°F target stays constant while the ice mass scales.
| Batch Water Weight | Required Mix Temperature | Crushed Ice Weight | Liquid Water Needed | Final Dough Temperature |
|---|---|---|---|---|
| [350g Ref]: 350g total water | mix at 2°F | substitute 140g ice | keep 210g warm water | friction +24°F absorbed |
| 100g Lighter: 300g total water | mix at 2°F | substitute 120g ice | keep 180g warm water | friction +24°F absorbed |
| 100g Heavier: 400g total water | mix at 2°F | substitute 160g ice | keep 240g warm water | friction +24°F absorbed |
| Half Batch: 250g total water | mix at 2°F | substitute 100g ice | keep 150g warm water | friction +24°F absorbed |
| Large Batch: 500g total water | mix at 2°F | substitute 200g ice | keep 300g warm water | friction +24°F absorbed |
On-Bench Hydration & Fermentation Adjuster
Modify base flour mass, levain inoculation, or ambient kitchen temperature below to recalculate from this 2°F (-16.7°C) baseline.
Baking Sourdough in a Hot 90°F Room: Why You Need 2°F Water (140g Ice)
Latent heat of fusion is why the cooling arithmetic is not linear. Replacing 140g of the 350g of water with crushed ice removes not merely 140g × 1 cal/g of sensible heat, but 140g × 80 cal/g of phase-change heat, which is what allows a 90°F (32.2°C) room to be cooled into a 74°F dough.
Water temperature and flour temperature trade off. A 2°F cooler mix water offsets a 2°F warmer flour, but only if the correction is applied before the two meet — once the flour is wet, the system is already committed.
Thermal Control Protocol for High-Friction Planetary Mixer (74°F DDT) in a 90°F Room
- Check for Sunlight: A 90°F (32.2°C) reading taken in direct sun is unreliable — move the bowl to the work surface and re-probe before you trust the arithmetic.
- Equalise the Levain: Pull the starter out of the refrigerator and let it come toward 90°F, because the levain is a third of the 4-factor equation and a cold levain silently drags the whole dough down.
- Build the Slush: Combine 140g of finely crushed ice with 210g of tap water at 78°F and stir until no shards remain.
- Mix, Probe and Trust: Run high-friction planetary mixer (74°f ddt) (+24°F), then confirm the dough reads 74°F ± 1°F before the fermentation clock starts.
Common Scaling & Troubleshooting Questions (2°F (-16.7°C))
Does the type of mixer actually change the water temperature?
Yes, and that is exactly what the friction factor models. High-Friction Planetary Mixer (74°F DDT) contributes +24°F, so the same 90 degrees (32.2°C) kitchen needs a 2°F mix water for this machine and a different one for a hand-mixed dough.
Why is my crumb gummy even though the dough looked the right temperature?
A correct 74°F dough can still bake badly if the core never reached 208°F. Check the internal temperature with a probe rather than trusting the oven dial, and remember to cool the loaf for two hours before slicing.
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 2°F target — but you must double the ice too, from 140g to 280g.