Watson Dairy Consulting

Pasteurisation Equivalence & P* Calculator

Compare holding times under an entered log-linear model and view a stated reference index. This does not validate a process or authorise a temperature deviation.

Calculation boundary: the time comparison uses the z-value you enter. The separate reference index uses 15 seconds at 72°C and z = 8°C. A value of one or more is not proof of pasteurisation compliance. Keep the required process specification and validate any proposed alternative against the product and applicable requirements.

Inputs

Mathematical examples: 72°C/15s compared at 71°C 72°C compared at 63°C, assumed z 4.3 75°C/15s compared at 72°C

Reference temp T₁ (°C)

Reference time t₁ (s)

Actual temp T₂ (°C)

z-value (°C)

Choose a z-value supported for the organism or enzyme, product and test conditions. Example values are assumptions, not regulatory acceptance criteria.

Results

Equivalent time at T₂—

Equivalent time at T₂ (minutes)—

P* of reference process (vs 72°C/15 s, z=8)—

Enter inputs to calculate.

Temperature (°C)	Equivalent time