Brew-day quick guide

This page is an operator guide for brew day. Use it directly when temperature behavior differs from expectation.

How to use this guide

1. Pick the matching symptom from the matrix below.

2. Apply only the first action.

3. Observe at least one full rest or one complete heat-up segment.

4. Only if the symptom remains, apply the second action.

Rule: Change only one control lever at a time.

2-minute pre-start check

• Volume matches AutoTune conditions (about +/-10%).

• Pump and stirrer state matches AutoTune conditions.

• Sensor values are plausible (no jumps, no obvious outliers).

• No plan to change multiple control parameters in parallel.

Starter profiles by setup (first run)

Setup	Starting point	First safe correction
20-30 L, strong circulation, IDS	AutoTune values + medium tuning factor	If overshoot appears, lower tuning factor slightly first
40-60 L, relay/PWM, medium inertia	AutoTune values + medium to defensive tuning factor	If heat-up is too slow, raise tuning factor in small steps
HLT or slow thermal system	AutoTune values + defensive tuning factor	If hold oscillates, lower tuning factor slightly before touching P/I/D

Symptom -> cause -> action

Symptom	Likely cause	First action	Second action
Overshoot > 0.5 K in enzyme range	Loop too aggressive or real inertia higher than tuning run	Lower tuning factor slightly	Review enzyme window/coasting, then fine-adjust P/I/D
Heat-up clearly too slow	Control style too defensive or changed circulation/volume	Verify circulation and volume realism	Increase tuning factor moderately
Rest hold unstable (constant corrections)	Sensor position/flow issue, implausible sa or psa	Check sensor location and mixing, validate sa/psa	Only then adjust I in small steps
Calm start, later oscillation near setpoint	Thermal delay underestimated	Check coasting behavior	Lower tuning factor slightly, optionally increase D carefully
AutoTune looked good, brew day differs	Boundary conditions differ between tune and production	Repeat AutoTune under real brew conditions	Apply manual PID correction only after retune

Limits of automation

If mixing is weak, sensors are mounted with high thermal lag, or heater power does not match volume, process physics dominates. In this case, improve setup and process first, then tune again.

See also

• AutoTune step by step

• PID instructions

• Troubleshooting