Peanut processing
Practical Action
A simple winnower to remove the skin from the nuts can be made by allowing the nuts to fall in a
gentle stream in front of an electric fan. The Heavy nuts will fall straight down while the lighter
skin will be blown away.
Traditionally women pounded the nuts between stones, a very time consuming activity. Now
nuts are often ground in a mill that may be powered by hand or with a motor. The type of mill
used will depend on the scale of production, The most commonly used mill is an adjustable plate
mill. The tighter the distance between the plates the finer the texture of the butter. The milling
process may have to be repeated to obtain the desired texture.
Salt may be added at this stage; about 2% by weight. A special anti-oxidant chemical may be
added to prevent rancidity, which will develop after a few months. However, to start with the
product will probably be sold very soon after manufacture. The peanut butter is then packed in
jars.
The type of peanut butter produced by this process is of the 'crunchy' variety, and adjustments
on the mill can produce varying textures. For the very smooth paste a more sophisticated milling
process is required, with the high levels of heat being produced during milling causing
difficulties.
To avoid separation of the oil and the settling out of the solids within the peanut butter after few
days of storing, the stabiliser called glyceryl monstearate (GMS) can be added to the at 2-3% by
weight (see Food Chain Journal number 30). It is suggested that all of the GMS is added to a
small amount of the peanut butter to form a premix and then this is mixed into the main batch.
This results in more even distribution of the small amount of GMS in the batch
References and Further Reading
The Manual Screw Press for Small-scale Oil Extraction,
This book describes the Practical Action oil press manufacture and use,
Oil Processing: Food Cycle Technology Source Book by UNIFEM,
This book has a broader coverage.
Small-scale Peanut Butter Processing in Tanzania Food Chain Journal Number
30 June 2002, ITDG.
Principles of Oil Extraction Technical Brief, Practical Action.
Peanut Roaster Technical Brief Practical Action South Asia (details shown
below).
Engineering drawings of the Practical Action screw press are available from
Practical Action Head Office, E-mail: infoserv@practicalaction.org.uk.
Practical Action South Asia has been involved in the design and development of a peanut roaster
for small-scale production, and should be able to supply names and addresses of local
equipment suppliers. Practical Action Southern Africa has produced peanut butter making
equipment.
Practical Action South Asia
5 Lionel Edirisinghe Mawatha
Kirulapone
Colombo 5,
Sri Lanka
Tel: +94 11 2829412
Fax: +94 11 2856188
E-mail:
general@practicalaction.lk
Practical Action Southern Africa
P.O. Box 1744
Harare
Zimbabwe
Tel: +263 4 91 403896
Fax: +263 4 669 773
E-mail: zimbabwe@practicalaction.org.zw
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