The Roaster Desk

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

Loring S15 Kestrel vs Diedrich IR-12

The ultra-efficient, fully automated convection powerhouse with an integrated afterburner. · The classic infrared drum roaster offering tactile manual control and exceptional value.

↔ Split verdict

The choice between the Loring S15 and the Diedrich IR-12 comes down to your business model, budget, and roasting philosophy. The Loring is an eco-friendly, highly automated convection…

Batch Capacity → S15 KestrelAutomation & Controls → S15 KestrelEmissions Control → S15 Kestrel

Also searched: Diedrich IR-12 vs Loring S15 Kestrel

Decision picker

For most buyers, we lean toward either platform depending on constraints. Which sounds closer to you?
Power users chasing control, throughput, or automation depth usually land on Loring S15 Kestrel. Your pick?
If capital outlay is the deciding factor, Diedrich IR-12 usually wins. Agree?

Specification matrix

Batch Capacity

Loring S15 Kestrel

33 lbs (15 kg)

Diedrich IR-12

26.4 lbs (12 kg)

Heat Transfer Dynamics

Loring S15 Kestrel

Convection-dominant (recirculating air bath)

Diedrich IR-12

Balanced conduction & convection (infrared burners)

Automation & Controls

Loring S15 Kestrel

12" touchscreen, fully automated recipe-driven profiles

Diedrich IR-12

Manual gas/air knobs, supports 3rd-party logging (Cropster/Artisan)

Emissions Control

Loring S15 Kestrel

Integrated afterburner (single-burner closed loop)

Diedrich IR-12

Requires separate external afterburner/catalytic oxidizer

Fuel Efficiency

Loring S15 Kestrel

Ultra-high (50-80% gas savings vs conventional drums)

Diedrich IR-12

Standard commercial consumption (~90,000 BTU/hr max)

Minimum Batch Size

Loring S15 Kestrel

~6.6 lbs (3 kg)

Diedrich IR-12

~1.0 lb (0.45 kg)

Upfront Capital Cost

Loring S15 Kestrel

Very High (>$100,000)

Diedrich IR-12

Moderate ($26,000 - $32,000)

Physical Footprint (WxLxH)

Loring S15 Kestrel

61" x 91" x 91" (integrated chaff/burner)

Diedrich IR-12

48" x 56" x 75" (excluding external burner)

Values from manufacturer documentation and dealer quotes. Confirm lead times, install kits, and utility requirements before purchase.

Strengths & trade-offs

Loring S15 Kestrel

  • Incredible fuel efficiency with up to 80% gas savings via recirculating design
  • Integrated afterburner simplifies urban permitting and reduces installation footprint
  • Advanced touchscreen automation ensures highly repeatable, recipe-driven roasts
  • Extremely high upfront capital cost (exceeding $100k)
  • Steep learning curve for roasters transitioning from traditional drum systems

Diedrich IR-12

  • Highly accessible entry price point (roughly one-third of the Loring's cost)
  • Excellent tactile, manual control over infrared burners and airflow
  • Outstanding batch flexibility with a very low minimum capacity of 1 lb
  • Requires a separate afterburner in strict emissions-regulated zones
  • Significantly higher gas consumption per pound roasted compared to Loring

Deep dives

At a glance

The Loring S15 (officially designated as the Falcon in the 15 kg class, though often compared under the Kestrel family lineage) and the Diedrich IR-12 represent two fundamentally different philosophies in commercial coffee roasting. The Loring is a highly automated, closed-loop recirculating hot-air system that integrates an afterburner directly into its single-burner design, prioritizing extreme energy efficiency, low emissions, and highly repeatable profile automation.

Where they diverge

In contrast, the Diedrich IR-12 is a traditional infrared drum roaster that balances conductive and convective heat transfer. It offers roasters a hands-on, tactile roasting experience with manual controls at roughly one-third of the Loring's capital cost, making it a beloved choice for craft-focused startups and budget-conscious operations.

How we researched this pair

Informed by manufacturer specifications for the Loring S15 Falcon and Diedrich IR-12, alongside real-world feedback from commercial roasting forums. Addressed the common naming confusion between the Loring S15 Falcon and S35 Kestrel. Evaluated thermal dynamics, gas efficiency claims, and urban permitting considerations.

What buyers report

Owners of the Loring S15 consistently praise its unmatched batch-to-batch consistency and thermal stability, noting that once a profile is dialed in, the machine repeats it flawlessly. Roasters operating in dense urban areas celebrate the integrated afterburner for making landlord negotiations and environmental permitting a breeze. However, some traditionalists note a learning curve when translating profiles to a convection-dominant system, and the high initial price tag remains a significant hurdle for bootstrapped startups.

Diedrich IR-12 users love the hands-on, artisanal feel of the machine, appreciating the fine control they have over the infrared burners and airflow. It is widely praised as a reliable workhorse that produces a classic, full-bodied cup. On the downside, some users complain about the lack of advanced built-in automation for high-volume production, and those in strictly regulated areas note that adding an external afterburner quickly drives up the initial footprint and cost.

FAQ

Does the Loring S15 Kestrel actually refer to the Falcon?
Yes. In Loring's official naming convention, the 15 kg model is named the S15 Falcon, while the 'Kestrel' moniker is reserved for their larger 35 kg model (S35). However, many in the industry use the terms interchangeably when discussing Loring's 15 kg capacity class.
Can I run small test batches on these commercial roasters?
The Diedrich IR-12 is far more flexible for small batches, capable of roasting as little as 1 lb (0.45 kg). The Loring S15 has a higher minimum batch size of approximately 6.6 lbs (3 kg), making it less suitable for micro-batch sample roasting.
Do I need a separate afterburner for these machines?
The Loring S15 features a patented single-burner design that acts as an integrated afterburner, incinerating smoke and odors internally. The Diedrich IR-12 does not have an integrated afterburner; depending on your local environmental regulations, you may need to purchase and install a separate external thermal oxidizer.
Which roaster is better for light, modern specialty coffees?
While both can roast excellent coffee, the Loring's convection-dominant, super-clean air path is highly favored by modern specialty roasters looking to highlight origin clarity, acidity, and sweetness without any risk of conductive scorching or drum-contact defects.
Is the Loring's high price tag justified by gas savings?
For high-volume operations, yes. The Loring's recirculating design can save 50% to 80% on gas compared to traditional drum roasters. Over several years of heavy daily production, these utility savings, combined with labor savings from automation, can offset the higher initial capital expenditure.

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