tags: [] - coffee/roasting - coffee/roasting/production aliases: - Roast yield - Weight loss calculation - Roasting yield percentage

Yield Calculation¶

Tags: #coffee/roasting #coffee/roasting/production Aliases: Roast yield, Weight loss calculation, Roasting yield percentage Related: Roasting MOC | Roast Weight Loss | Moisture Loss | Density Loss | Inventory Management Status: ✅ Complete

Overview¶

Yield calculation in coffee roasting quantifies the amount of roasted coffee produced from a given weight of green coffee, expressed as a percentage of the green coffee input weight. The yield percentage is directly related to roast weight loss — the mass reduction that occurs during roasting from moisture evaporation, CO₂ release, and volatile compound loss. Yield calculation is a fundamental production metric in any commercial roastery: it affects costing, inventory management, batch planning, and the financial viability of roasting operations.

The Yield Formula¶

Roast yield is calculated as:

Yield (%) = (Roasted weight / Green weight) × 100

Or equivalently, roast weight loss percentage is:

Weight loss (%) = ((Green weight − Roasted weight) / Green weight) × 100

Note that: Yield (%) + Weight loss (%) = 100%

Example¶

Green coffee charged: 15.0 kg
Roasted coffee collected: 12.45 kg
Weight loss: (15.0 − 12.45) / 15.0 × 100 = 17.0%
Yield: 100 − 17.0 = 83.0%

Typical Yield Ranges by Roast Level¶

Yield decreases as roast level increases — darker roasts lose more mass from additional moisture, CO₂, and volatile compound evaporation:

Roast level	Typical yield range	Typical weight loss
Very light (Cinnamon, Scandinavian)	87–90%	10–13%
Light (City)	85–88%	12–15%
Light-medium (City+)	83–86%	14–17%
Medium (Full City)	81–84%	16–19%
Dark (Full City+, Vienna)	78–82%	18–22%
Very dark (French, Italian)	74–80%	20–26%

These ranges vary by origin, processing method, and batch size. High-moisture green coffee (e.g., Indonesian wet-hulled) loses more mass during roasting than lower-moisture lots at the same roast level, producing lower yield.

Yield and Production Costing¶

Yield directly affects the cost per kilogram of roasted coffee. If green coffee costs $10/kg and yield is 84%, the green coffee cost component of the roasted coffee cost is:

Green coffee cost per kg roasted = Green coffee price / Yield = $10.00 / 0.84 = $11.90/kg

A roastery that improves yield from 82% to 85% on a 100 kg/week production reduces its green coffee cost component meaningfully over the course of a year. Darker roasting styles incur significantly higher effective green coffee costs per kilogram of sellable product.

Yield in Batch Planning¶

When scheduling production, yield is used to calculate the green coffee quantity required to produce a target weight of roasted coffee:

Green coffee required = Target roasted weight / Yield

If 20 kg of roasted coffee is needed and expected yield is 84%: Green coffee required = 20 / 0.84 = 23.8 kg

Cooling Loss vs. Drop Yield¶

Roasters sometimes distinguish between two measurement points: - Drop yield: Weight of beans immediately after discharge into the cooling tray (still slightly warm; includes residual steam loss in the first seconds of cooling) - Cold yield / cooled yield: Weight after full cooling to ambient temperature (the practical production yield)

The difference between drop yield and cold yield is small (typically 0.2–0.5%) but can be significant at high production volumes. Consistent measurement at one defined point is more important than which point is chosen.

Tracking Yield for Quality Control¶

Consistent yield tracking across batches of the same green coffee provides a secondary quality consistency indicator: - Significant yield variation (±1.5% or more) at the same target profile and batch weight indicates variability in the roasting process (burner consistency, ambient conditions, weighing errors) - Systematically lower yield over time from the same green coffee can indicate increasing drum or airflow system fouling, or a drifting probe reading causing hotter actual temperatures

Key Facts¶

Yield (%) = (Roasted weight / Green weight) × 100; typical range 80–89% depending on roast level
Darker roasts produce lower yield (more mass loss); very dark roasts (French, Italian) yield 74–80%
Yield directly affects production cost; lower yield means higher effective green coffee cost per kg of roasted product
Batch planning: green coffee required = target roasted weight / yield
Track yield per batch alongside other profile metrics; systematic yield drift indicates process or equipment change

References¶

Changelog¶

Date	Change
2026-04-27	Note created

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