In urban and sub-urban areas of Sri Lanka, roadside peanut vendors are a common sight. This is
because roasted peanuts are a popular snack and there is a good market. The street vendors use
a small open pan with sand as a roasting agent (sand bath) to roast the shelled peanuts. The
fuel sources most commonly used are gas and kerosene. These roasters are not very efficient
and the sand can be harmful to the body. Medium-scale manufacturers who have access to
larger amounts of capital hire bakery ovens to roast peanuts. The peanuts are spread in a
shallow pan and put into the oven and roasted over a moderate heat. There are also gas fired
high-cost peanut roasters available in the country. These are efficient and less troublesome (as
opposed to using the other two methods) yet they are not affordable to small-scale food
Practical Action South Asia’s involvement in developing an appropriate peanut roaster for small
scale food processors stems form a request from an NGO called Vinivida in 1995. One of their
beneficiaries was involved in peanut roasting and had inquired about a more efficient way of
The apparatus is basically a manually operated rotating drum that is heated externally. This
structure is housed in a brick and clay construction (similar to a small-scale bakery oven). The
roaster can be fabricated at any welding workshop and has no high technology components. An
ordinary mason can do the installation and construction of the hearth.
This roaster does not need gas or kerosene but uses paddy husk, sawdust or peanut shells as a
fuel source. This is a low cost, freely available raw material and it is also a waste product from
other industries. Peanut shells are normally not re-used and disposal can be a problem. Using
the shells as a fuel source alleviates the problem.
30 kg of peanuts takes 30 minutes to roast. Plus the peanuts are evenly roasted with fewer
losses due to over roasting.
The roaster could also be used to roast coffee, condiments, chilli, herbs or similar commodities.
Advantages over the present equipment
A sand bath is not used and there are no health risks.
The continuous rotation of the drum throughout the process results in uniformly roasted
The producer has a control over process and timing.
A solution to peanut husk/shell disposal as well as re-using by products (paddy husks/
Low fuel costs
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