Key Elements

Materials must be sufficiently dry. Hand equipment can be used. For mechanisation of the grinding process a hammer mill is needed

Description/Implementation

All vegetables can be ground if they are sufficiently dry. Drying of vegetables is described in detail in 'preservation of foods' (Agrodok 3, page 23 to 34). One may grind products manually or mechanically. One may use the following equipment for grinding dried vegetables:

* a pestle and mortar for manual grinding

* a hammer mill for mechanical grinding; a hammer mill is made of a cage containing rapidly moving knives. The dried vegetables are broken and pulverised. Much power is needed.

* a roller mill for mechanical grinding; two smooth cylinders rotating in opposite directions of contact. If one can adjust the distance between the cylindrical rollers, the size of granulated products may be varied.

* a millstone grinder: particular hard products, such as pulses, may be ground between two stones, one stationary, the other moving. More information on these mills can be found in "Small-scale food processing, a guide to appropriate equipment by Follows and Hampton." (see attached bibliographical record)

Ginger

Mature ginger can be held some weeks before processing. Older ginger becomes more fibrous, but also more pungent. In the early half of the season ginger is fleshier and can be dehydrated whole for sale as dried whole-root ginger. In the latter part of the season the skin is hard and rather impermeable to moisture transfer; thus the green ginger must be sliced into 3 mm. thick pieces to ensure quick even drying. The dried product can be sold directly or processed to ginger powder. This is made by pulverising the dry ginger to a mesh size of 50 - 80 (= 175 - 325 m). The material is fairly fibrous at the stage of harvest. The obvious choice for the initial breaking up of the hard pieces appears to be hammer mills; in the latter stages with smaller sized pieces, other mills could be used.

Garlic

For making garlic-powder garlic should be harvested 10 - 15% earlier than garlic for direct human consumption (this means that when you normally harvest the garlic after 100 days, you should now harvest it after 85 to 90 days). Early harvest will avoid sprouting. After harvest and possible storage, you must first peel the garlic and wash it. Then you slice it in pieces of 3 to 4 mm, by which rings arise. The dried product can be consumed directly, in pieces of 2-3 mm or ground to powder to a mesh size of 100 (= 160 m).

Onions

For drying and grinding onions they should be harvested as late as possible. The onions then contain relatively little water and most dry matter. The quality of the outer shell will be lower, but this shell is removed before drying. After peeling, the onions are sliced into pieces of 3 mm and dried. The dried product can be consumed directly or grind to powder to a mesh size of 55 (=250 m). Onions and garlic are dry enough when they are brittle, and when they can be rubbed to powder between the fingers.