Proof box drift and loaf variability

We’re seeing a repeatable 2–3 mm variance in sandwich loaf slice height when the proof box wanders from 28°C to 31°C during a 90‑minute proof, confirmed with a calibrated probe. Has anyone tightened this up without bumping humidity past 75% or changing yeast load — maybe through rack load balancing or stricter door-open limits?

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Try ‘prewarm the racks’ — roll them in empty for 10–15 minutes so the steel isn’t a heat sink; treat the racks like radiators, not ice packs — and stagger pans for even airflow; that cut our variance to about ±1 mm without pushing RH… If your controller lets you tighten the temp deadband (±0.3°C) or drop fan speed during hold, can you tweak those?

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