The Roaster Desk

By Kai Nakamura · Production roaster & equipment editor · Updated 2026-09-21

Mill City 15kg vs Diedrich IR-12

Production throughput under real utility constraints

→ Mill City 15kg

Mill City 15kg wins on installed cost — confirm Diedrich dealer support in your region before ruling it out.

Capital outlay → MillHourly throughput → MillAutomation depth → Diedrich

Also searched: diedrich ir-12 vs mill city 15kg

Decision picker

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

Specification matrix

Batch capacity

Mill City 15kg

15 kg

Diedrich IR-12

12 kg

Heat source

Mill City 15kg

450,000 BTU/h gas

Diedrich IR-12

400,000 BTU/h gas

Drum / chamber

Mill City 15kg

Carbon steel drum

Diedrich IR-12

Double-wall IR drum

Batch time (typical)

Mill City 15kg

14 min

Diedrich IR-12

14 min

Throughput (modelled)

Mill City 15kg

50 kg/h

Diedrich IR-12

40 kg/h

Street price band

Mill City 15kg

$55,000 USD

Diedrich IR-12

$95,000 USD

Exhaust

Mill City 15kg

950 CFM

Diedrich IR-12

900 CFM

Lead time

Mill City 15kg

12 wks — confirm with dealer

Diedrich IR-12

16 wks — confirm with dealer

Automation

Mill City 15kg

Optional Cropster bridge

Diedrich IR-12

IR control panel

Service hub

Mill City 15kg

USA

Diedrich IR-12

USA

Manufacturer specs and dealer quotes. Throughput model uses SCA 4-minute cooling allowance. Verify all numbers with OEM before purchase.

Strengths & trade-offs

Mill City Roasters strengths & gaps

  • Mid-tier production capacity
  • Competitive pricing
  • Higher gas use than Loring

Diedrich strengths & gaps

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

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.

What to verify with your dealer

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

FAQ

Looking for diedrich ir-12 vs mill city 15kg?
Same comparison — Mill City 15kg is listed first by convention. Verdict and spec matrix are identical either way.
What throughput can I expect?
Modelled: 50 kg/h (Mill City 15kg) vs 40 kg/h (Diedrich IR-12) including a 4-minute charge/cool cycle.
What street price should I budget?
Mill City 15kg: $55,000 USD (As quoted Q1 2026, US factory). Diedrich IR-12: $95,000 USD (As quoted Q1 2026, ex-install). Request refreshed quotes — neither includes install.
Which supports Cropster logging?
Mill City 15kg: Yes with RT bridge — confirm with dealer. Diedrich IR-12: Yes with RT bridge — confirm with dealer.

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