Choosing the right capacity is the most consequential decision when buying a commercial coffee roaster. Too small and you cap your growth; too large and you overpay for idle capacity.
What Does Roaster Capacity Actually Mean?
Capacity = maximum green bean weight per batch. Green beans lose 15-20% weight during roasting, so a 12 kg charge yields ~10 kg roasted. Factor in cycle time (12-18 min roast + 5 min cooling) and you get 3-4 batches per hour.
| Roaster Size | Batches/Hour | Daily Output (8 h) |
|---|---|---|
| 6 kg | 3-3.5 | ~108 kg roasted |
| 12 kg | 3-3.5 | ~216 kg roasted |
| 30 kg | 2.5-3 | ~500 kg roasted |
| 60 kg | 2-2.5 | ~920 kg roasted |
The 6 kg Roaster: Best for Specialty Cafes and Micro-Roasteries
The 6 kg drum roaster is the entry point of serious commercial roasting. It produces enough volume to serve a cafe, supply a handful of wholesale accounts, or run a boutique subscription service without requiring industrial infrastructure.
Who should buy a 6 kg roaster?
- Specialty cafes roasting in-house for retail and bar consumption
- Micro-roasteries with 50-150 kg/week green bean intake
- Operations expanding from a 1-3 kg sample roaster to commercial scale
- Buyers where a larger machine requires costly infrastructure upgrades
The Yoshan SD-6KG is popular for operators wanting proven drum mechanics at a competitive price. The YS-6 adds Siemens PLC touchscreen control for full profile repeatability.
The 12 kg Roaster: The Commercial Sweet Spot
The 12 kg roaster is the most widely sold commercial size globally. It doubles 6 kg throughput without requiring three-phase power or industrial ventilation that larger roasters demand.
Who should buy a 12 kg roaster?
- Wholesale coffee suppliers serving 10-30 cafe accounts
- Cafe chains with a central roasting facility
- E-commerce roasters fulfilling subscription orders
- Operators running 1-2 shifts per day with room to scale
The 30 kg Roaster: Serious Volume
Once you cross 400 kg/day in demand, a 12 kg machine becomes a bottleneck. The 30 kg roaster is built for contract roasters, regional distributors, and OEM producers needing consistent high-volume output.
Who should buy a 30 kg roaster?
- Contract roasters fulfilling private-label orders for supermarkets or hotel chains
- Regional coffee distributors with large wholesale accounts
- Operations running two or more shifts per day
At this size, three-phase electrical supply is a requirement. Automation is also more important: manual control at 30 kg introduces consistency issues. The Yoshan YS-30 comes standard with Siemens S7-1200 PLC.
Quick Selection Guide
| Weekly Green Bean Volume | Recommended Size | Yoshan Models |
|---|---|---|
| Under 300 kg/week | 6 kg | SD-6KG, YS-6 |
| 300-900 kg/week | 12 kg | SD-12KG, YS-12KG |
| 900-2,500 kg/week | 30 kg | SD-30KG, YS-30 |
| 2,500-6,000 kg/week | 60 kg | SD-60KG |
| Over 6,000 kg/week | 120-300 kg | SD-120, SD-300 |
Three More Factors
1. Gas vs Electric
Almost all commercial roasters above 3 kg use natural gas or LPG – faster response, cheaper to run, better roast curve control. Electric is practical only for sample roasters under 1 kg.
2. Manual vs Automated Control
Manual dial-control requires an experienced operator for every roast. PLC machines store profiles digitally so every batch follows the same curve automatically. For high batch counts, automation pays for itself quickly in consistency and labour savings.
3. Budget and Total Cost
Machine price is only part of the equation. Yoshan machines offer 40-60% savings vs European brands for comparable specifications while using the same key components (Siemens PLC, CE-certified electrical).
