Solar milk pasteurizer improves smallholder farmer profits

Using a solar milk pas­teur­izer, small­holder farm­ers seek­ing to min­im­ize milk losses along the mar­ket­ing chain es­pe­cially in the arid and semi-arid lands has been de­veloped by the Kenya Ag­ri­cul­tural and Live­stock Re­search Or­gan­iz­a­tion.  The new tech­no­logy will help milk farm­ers and busi­ness vendors pro­long the shelf life of milk and hence im­prove mar­ket- abil­ity and gen­er­ate more in­come.

Milk mar­ket­ing is an im­port­ant in­come earn­ing op­por­tun­ity for people in the arid and semi-arid lands (ASALs) of Kenya. For a long time, farm­ers have been using lim­ited fire­wood to boil the milk hence pla­cing in­tense pres­sure on the forests and des­troy­ing the en­vir­on­ment.

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The solar milk pas­teur­izer con­sists of a flat-plate water heat­ing solar col­lector and a stain­less steel cyl­indrical milk con­tainer. Water in the solar col­lector is dir­ectly heated by the sun and the hot water pro­duced used for pas­teur­iz­ing milk.  

Ac­cord­ing to Marsabit KALRO of­ficer F.​Wayua, the abund­ant solar en­ergy in ASALs can be used to pas­teur­ize milk. A simple solar milk pas­teur­izer can be made loc­ally with the aid of jua kali ar­tis­ans. The ma­ter­i­als re­quired for fab­ric­a­tion in­clude a flat plate solar col­lector, a stain­less steel cyl­indrical tank, con­nect­ing pipes& valves and in­su­lat­ing ma­ter­i­als (fiber glass, cot­ton, wool and saw dust). The ma­ter­i­als can be ob­tained from nat­ive hard­ware shops close to the farm­ers’ res­id­ence.

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After as­sem­bling and the device is ready for use, it is ad­vis­able to tilt the solar col­lector at 10-15° from the ho­ri­zontal, fa­cing the equator. En­sure you have good qual­ity milk to be pas­teur­ized and a piece of clean sterile (boiled) cot­ton cloth.

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Pro­ced­ure for Milk Pas­teur­iz­a­tion

• Pas­teur­iz­a­tion should be done between 10 am and 4 pm when there is ad­equate solar ra­di­ation
• Fill the sys­tem with water in the morn­ing
• Sieve milk using the cot­ton cloth
• Pour the sieved milk in the milk con­tainer
• Water in the solar col­lector is dir­ectly heated by the sun
• The hot water pro­duced is used for pas­teur­iz­ing milk in the milk con­tainer
• Cir­cu­la­tion of hot water from the col­lector to the jack­eted milk con­tainer con­tin­ues as long as the sun is shin­ing
• Let the milk heat to 63°C and hold for 30 minutes or 85°C (when it starts to foam) and hold for 5 seconds.

The device is re­com­men­ded for pro­du­cers and milk traders in arid pas­toral areas as they have lim­ited ac­cess to grid elec­tri­city but have plenty of solar ra­di­ation. Milk Pas­teur­iz­a­tion makes milk safe for human con­sump­tion.

 For more in­form­a­tion con­tact: Centre Dir­ector, KARI Marsabit P.O. Box 147 – 60500 Tel. 069 – 2040 Wire­less: 020 801 7018 Email: kuriasg@​gmail.​com