STORAGE

Once dried the quality of coffee remains stable for many months if kept in the correct conditions.

When building storage for parchment or cherry green coffee a number of considerations need to be considered to maintain the product quality. Basic building parameters are as follows:

Buildings face an east-west, north-south plan with long sides on east-west and short sides of the building where the sun travels most through the day.
Avoid low humid areas for any warehouse location.
The store should be well ventilated.
There is a constant temperature and humidity not exceeding 22°C and 60% RH.
Foundations are insulated and weatherproof.
Thermal insulation is built into the design.
Buildings are structurally sound, pest proof and free from leaks.
A sealed, waterproof and impervious concrete floor.
Avoid natural light to retain product quality. Where artificial light is used it should be shatterproof lighting.
Monitor temperature and humidity of the store in several places.
Contract a pest control programme on site.

When storing coffee within the warehouse place bags:

On dry, clean and sound pallets.
At least 0.8m away from walls.
In dark condition the majority of time.
Away from doors and windows that open regularly.
Keep at least 2m from the top of a coffee stack and the ridge of the roof.

BAG TYPES

Do not store parchment or dried cherries in jute because it leads to a fast deterioration of cup quality and can taint. Studies have shown that hermetic big bags offer an excellent method of preserving quality over extended periods in storage.65

Big bags need a forklift truck (ideally gas or electric powered to limit fumes in the warehouse) and as such require significant capital investment. Where this is not possible, storage in grainpro bags is preferential. If using grainpro bags, these can be placed inside jute to improve coffee stack stability.

LOT SEPARATION

Lot separation, identification and monitoring quality changes over time are essential elements of good stock control. Keep the best quality lots at the opposite end of the store to poorer, possibly defective off grades to prevent taints. Assess coffees on a monthly basis to determine if physical and sensorial characteristics are maintained.

During transport to storage bagged coffee is covered to prevent contamination or weather damage. Once coffee arrives at a warehouse all lots must be checked for moisture content and for signs of pests or infestation.

Coffee is a hydroscopic food and can absorb both moisture and taints from the surrounding environment. For this reason it is always stored separately from materials with strong odours. These can include:

Tobacco
Spices or herbs
Defective coffees
Chemicals or fertilizers
Engine fumes

STORAGE PERIOD

Milling coffee directly after processing produces known problems. Astringent cup profile is common and colour can fade quickly. Conversely, coffee quality in both cup score and appearance is improved if it is given a resting period of three months before milling66. Cup quality is maintained for longer periods beyond three months if coffee is stored in parchment form (for washed or pulped natural coffee) or dried cherry (for natural processed coffee) and it is important to keep coffee in this form until the final preparation for market.

Storage