The Roaster Desk

By Kai Nakamura · Production roaster & equipment editor · Updated 2026-09-17

Diedrich IR-12 vs Probat P12 III

American IR drum vs German cast-iron at 12 kg

↔ Split

Diedrich IR-12 and Probat P12 III split on capex vs operating cost — your utility bill decides.

Hourly throughput: WinnerAutomation depth: Winner
Lowest street price → DiedrichFaster batches → DiedrichIR radiant profile → Diedrich drum physics

Also searched: probat p12 iii vs diedrich ir-12

Decision picker

What is your primary constraint?
Batch size you roast most often?
Is gas already permitted on-site?

Specification matrix

Batch capacity

Diedrich

12 kg

Probat

12 kg

Heat source

Diedrich

400,000 BTU/h gas

Probat

420,000 BTU/h gas

Drum / chamber

Diedrich

Double-wall IR drum

Probat

Cast-iron drum

Batch time (typical)

Diedrich

14 min

Probat

15 min

Throughput (modelled)

Diedrich

40 kg/h

Probat

37.9 kg/h

Street price band

Diedrich

$95,000 USD

Probat

$110,000 USD

Exhaust

Diedrich

900 CFM

Probat

950 CFM

Lead time

Diedrich

16 wks — confirm with dealer

Probat

20 wks — confirm with dealer

Automation

Diedrich

IR control panel

Probat

Probatronic 800 optional

Service hub

Diedrich

USA

Probat

Germany
Airflow ctrlThermal stab.Drum speedAutomationCapex value
IR-12III

Qualitative scores — verify against your roast program

Why this split

Neither platform dominates — Diedrich and Probat split on the constraint you named in the picker.

Airflow path through a commercial drum roaster from burner to cyclone
Typical drum roaster airflow: burner → drum → cyclone chaff collector

Deep dives

IR radiant heat transfer

Diedrich IR drums radiate through a double-wall — different first-crack timing than convection.

Operators switching from Probat or Giesen need 15–20 calibration batches, not a copied profile.

  • Log development time ratio across 3 charge weights
  • Compare ground colour at same end temp
What to verify with your dealer

Neither OEM publishes binding street prices — quotes move with queue and freight.

Verify with vendor

  • Confirm Diedrich IR-12 lead time and freight to your dock
  • Confirm Probat P12 III install kit and probe package included
  • Ask for three references at similar elevation and batch size

Side-by-side

Diedrich strengths & gaps

  • Infrared precision
  • Strong US service network
  • Higher gas consumption vs Loring

Probat strengths & gaps

  • Century-old engineering
  • Global parts network
  • Traditional gas hog

FAQ

Looking for probat p12 iii vs diedrich ir-12?
Same comparison — Diedrich IR-12 is listed first by convention. Verdict and spec matrix are identical either way.
What throughput can I expect?
Modelled: 40 kg/h (Diedrich IR-12) vs 37.9 kg/h (Probat P12 III) including a 4-minute charge/cool cycle.
What street price should I budget?
Diedrich IR-12: $95,000 USD (As quoted Q1 2026, ex-install). Probat P12 III: $110,000 USD (As quoted Q1 2026, EU/US dealer). Request refreshed quotes — neither includes install.
Which supports Cropster logging?
Diedrich IR-12: Yes with RT bridge — confirm with dealer. Probat P12 III: Aftermarket probe required.

Related comparisons