Cherry-to-green conversion

Reference values#

Values as reported. Moisture is wet basis where the source states it; “n.s.” means basis not stated. Cenicafé 2008 values are for Variedad Colombia from nine lots in Caldas, harvest 2005–2006; “selected” is ripe coffee separated from the harvest, “unselected” the harvest as it came.¹

Fresh weight and dry matter#

The share of a fruit layer depends on the basis. Pulp is about 43–44% of the fresh fruit’s weight,^1,9 but only about 30% of its dry matter.⁸ Fresh pulp holds about 80% moisture (basis not stated),⁸ washed parchment coffee about 53% (wb),² so the pulp’s share shrinks on a dry basis.

The dry matter is also a check on measured ratios. In the Cenicafé data, 39.1 kg of washed coffee per 100 kg of cherry at 53% moisture holds 18.4 kg of dry matter; 20.2 kg of dry parchment at 11% holds 18.0 kg (our arithmetic from the ratios and moisture values^1,2). From washed coffee onwards, almost all the mass lost is water.

Mass balance arithmetic#

All formulas use moisture in per cent; m is mass.¹⁰ The wet and dry bases are explained under moisture and water activity.

The FAO chapter illustrates the two bases with grain: if 100 kg of moist grain loses 20 kg of water on drying, it held 20% moisture on a wet basis and 25% on a dry basis.¹⁰ The Brazilian robusta study used the reference-moisture correction to express every sample at 12%.⁷

Worked examples#

Each example uses published inputs; the arithmetic is ours.

1. Wet to dry basis. Washed coffee at 53% (wb)² holds 53 kg of water and 47 kg of dry matter per 100 kg. On a dry basis that is 100 × 53 ÷ 47 = 112.8% – more water than dry matter.
2. Drying washed coffee. 1,000 kg of washed coffee at 53% dried to 11% (wb)²: m₂ = 1,000 × 47 ÷ 89 = 528.1 kg of dry parchment. Water removed: 471.9 kg. Cenicafé’s own figure from 280 kg of washed coffee is about 148 kg of dry parchment at 11%, the same proportion.²
3. Over-drying costs weight. Drying the same 1,000 kg to 10% instead of 11% gives 1,000 × 47 ÷ 90 = 522.2 kg, 5.9 kg less. Cenicafé lists losses per 1,000 kg of washed coffee of 5.9, 8.8, 11.6, 14.4 and 17.5 kg of dry parchment at 10, 9.5, 9, 8.5 and 8% moisture.² The table does not state the reference moisture; the formula, measured against drying to 11%, reproduces the first four and gives 17.2 kg for the last.
4. Cherry to green with factors. 2,000 kg of selected ripe cherry × 0.20 = 400 kg of dry parchment; × 0.80 = 320 kg of green coffee. Cenicafé’s direct factor from cherry to green, 0.16, gives the same 320 kg.^1,5
5. Natural coffee by standard ratios. 1,200 kg of fresh cherry ÷ 3 = 400 kg of dried cherry; × 0.50 = 200 kg of green coffee.^5,6 By moisture alone, fruit at 60% dried to 12% (both wb) would weigh 1,200 × 40 ÷ 88 = 545 kg (see Open questions).
6. Colombian factor de rendimiento. Excelso (kg) = dry parchment (kg) × 70 ÷ factor. At the reference factor of 94,⁴ 940 kg of dry parchment gives 700 kg of excelso – ten 70 kg bags. At 104.7, the mean of unclassified lots in the 2025 study, it gives 628.5 kg.⁴
7. Correcting to a reference moisture. A sample of 1.50 kg of green coffee at 14% moisture (wb) equals 1.50 × 86 ÷ 88 = 1.47 kg at 12% (wb), the reference used in the robusta study.⁷

Trade yield measures#

ICO factors. For its statistics, the ICO converts dried cherry to green coffee by multiplying by 0.50 and parchment coffee by multiplying by 0.80.⁵ The same rules convert roasted coffee with 1.19 and soluble coffee with 2.6.⁵

Colombia: factor de rendimiento. In Colombia, dry parchment is valued by its milling yield, and a lower factor indicates higher quality and price.⁴ Cenicafé defines the rendimiento en trilla as the quantity of dry parchment coffee needed for a 70 kg bag of excelso.¹ In 2008 the national base line for trade was 92.8 kg of dry parchment.¹ A 2025 study gives the reference value as 94: 94 kg of dry parchment give 70 kg of excelso and 6.3 kg of pasilla.⁴ Pasilla is the defective fraction sorted out of the green coffee.¹ Measured factors in 2008 were 90.75 for selected and 95.99 for unselected coffee.¹ In 2025, the best value was 92.33 on the farm and 90.01 at Cenicafé’s own processing plant.⁴

Excelso and pasilla together make up 76.3 of the 94 kg, about 81% of the dry parchment (our arithmetic⁴). That is close to the factor of 0.80 for parchment.^1,5

Volume measures. Where harvests are counted in volume, bulk density converts volume to mass. At Cenicafé’s 622 kg/m³ for fresh fruit, 1,000 L of cherry weigh about 622 kg (our arithmetic¹). No official Brazilian reference for volume of field coffee per 60 kg bag was found in the sources opened for this entry, so none is given.

Bulk density along the chain#

Bulk density – mass per volume of a heap, air gaps included – changes at every step. Cenicafé measured it by free fall (Colombian standard NTC 4607) for each state of the coffee.¹ Pulped coffee in its mucilage is the densest heap, at 827 kg/m³; dry parchment the lightest coffee state, at 391 kg/m³.¹

Bulk density also shifts within a stage. In arabica parchment coffee dried in the laboratory, bulk density fell from 518.58 to 448.62 kg/m³ as the coffee dried; seeds without parchment did the opposite.¹² Values from different methods differ, so compare only values measured the same way; see bean size and density.

Where the numbers vary#

• Sorting. In the 2025 Colombian study, classifying at three points (fruit by density before pulping, pulped coffee by size, parchment by density in washing) raised the ratio from 4.33 to 5.87 kg of cherry per kg of dry parchment.⁴ The classified lots also needed less parchment per bag: a factor of 97.22 against 104.7.⁴
• Ripeness. The robusta study set the outturn of unripe fruit at 19%, and its field outturn index, which allows for unripe fruit, was 22.57% against 24.68% for the plain index.⁷
• Specialty grading. Rejecting defects, mostly at the later stages, pushed the Ethiopian cooperatives to 8:1–11:1.⁶
• Final moisture. Each point of over-drying costs weight that is sold by the kilogram (see example 3).²
• Reference basis. A ratio means little without the moisture of the end product. The robusta study corrected to 12%;⁷ the Cenicafé ratios refer to parchment dried to 11–12%.¹

Open questions#

• No source opened for this entry measured cherry-to-green ratios for honey or pulped natural coffee.
• The standard 3:1 ratio from fresh to dried cherry⁶ is larger than a pure water balance predicts. Fruit at 50–60% moisture (wet basis)¹¹ dried to 10–12% gives about 1.8–2.3:1 (1.76 for 50% → 12%, 2.25 for 60% → 10%; our arithmetic with the drying formula¹⁰); 3:1 would need fruit at about 70–71% moisture (wb), or losses beyond water. Which losses make up the gap is not shown in the sources opened.
• How the 18% hulling loss and the 20% parchment share in the same Cenicafé table relate to each other is not explained in the source.¹
• Arabica and canephora were measured in different studies, places and processes. No study opened for this entry compared both species under one protocol.

Key studies#