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< prev - next > Food processing Herbs and spices KnO 100198_Clove Processing (Printable PDF)
Cloves are the unopened flower buds of
the evergreen tree Eugenia caryophyllus.
The tree is native to the Moluccas
(Spice Islands), which are part of the
Indonesian islands. It was taken to
Mauritius and then on to the islands of
Zanzibar and Pemba on the East African
coast during the 18th Century. Zanzibar
and Pemba are now the worlds largest
producers of cloves.
Cloves must be dried before they are
stored and sold for market. This brief
outlines the important steps that should
be taken pre-harvest and post-harvest to
ensure that the dried cloves are of top
quality for the market.
Figure 1: Dry cloves. Photo: Neil Noble / Practical
Clove production
The clove tree is a small evergreen tree that grows to a height of 12-20 metres. It thrives in
coastal regions with temperatures between 15 and 30°C, average rainfall and a distinctive dry
season (the optimum level of rainfall is 1750 to 2500mm a year). It is a low altitude plant that
grows best at altitudes lower than 300m above sea level although it will also grow at altitudes
above 900m.
The young leaves of the clove tree are bright pink and change to a greenish yellow as they
mature. The flowers develop in clusters of three to ten groups, each with three flowers per
Clove trees are first harvested when the tree is 6-8 years old. The timing of harvest of the clove
buds is critical. The buds should be harvested before the purple or crimson flowers start to
develop. The correct time of harvest is when the outer green leaves (the calyx) of the flower bud
change from olive green to yellow pink and before the petals fall to expose the stamens. Clusters
of flower buds are hand-picked from the branches. It is important that the branches are not
removed or damaged as this will reduce the yield of future crops.
After harvest the buds are detached from the stalks by holding a cluster in one hand, pressing it
against the palm of the other hand and slowly twisting so that the buds fall off. The hands of
the processor and the room in which the buds are separated must be very clean to prevent
contamination of the cloves. The stems and buds are separated and dried separately. The stems
can be used for oil distillation.
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