Shortage of Caustic Soda for Cleaning Milking Machines

New Zealand Journal of Agriculture, Volume 75, Issue 1, 15 July 1947, Page 8

Shortage of Caustic Soda for Cleaning Milking Machines

FOR the past 30 years caustic soda has been consistently recommended by the Dairy Division as the most satisfactory chemical to be used for cleaning milking machines and the method is described in Bulletin No. 118, “Cleaning of Milking Machines.” However, owing to the coal shortage and other production difficulties in England, normal supplies of caustic soda are not available for export. Imports of caustic soda and other alkalis such as soda ash and trisodium phosphate are reaching New Zealand in reduced amounts, so that during the coming dairy season in many districts there may be a temporary shortage of these chemicals. _

’T’O meet the present. need for some t alternative cleanser . for milking, machines . and dairy utensils the Dairy Division finds it necessary to recommend soap. In the past this has been used with success by a few careful farmers,-but cases have often occurred where the use of soap proved unsatisfactory because sufficient care was not taken to rinse it out of the machine with boiling water. Deposits of soap were found to accumulate in the machine and to give rise to a bad flavour, especially in cream. Because of 'such failures the Division has been reluctant in the past to encourage the use of soap. ■ The method to be used is the same as described in Bulletin No. 118. As soon 'as the milking is finished large quantities of clean cold water should be flushed through the teat cups till it runs clear from the releaser. It is hardly possible to use too much cold water, as that helps to prevent the formation of milkstone deposits in which millions of germs can develop and contaminate the milk. Liberal rinsing with cold water at this stage is particularly necessary where soap is used, and it has a greater tendency to- build up deposits.. The dirt on the outside of the teat. cups and claw rubbers must then be washed off with

some hot, soapy water and the equipment rinsed with clean hot water. The next step' is to flush out the machine with a solution of soap in boiling water, in the same-way as when using . caustic soda. To prepare the soap solution, place two or three pieces of common soap about the size of a large walnut in an ordinary domestic soap-shaker. As the boiling, water is running into the bucket stir the soap-shaker ; to dissolve the soap and produce a good lather. Alternatively, a bar of soap may be fixed on a piece of board with. nails ■ and stirred in the bucket of . boiling water. The use of a scrubbing brush to make the soap solution is not recommended, as it ; produces many small fragments of soap, and if these do not dissolve completely, they may settle inside the machine. - , ' ■' ’ The , hot soapy, water is drawn through the machine, at least 1 gallon being put through each set of teat cups. A can or bucket may be placed at the releaser .or vacuum tank to collect the soapy water for use later to wash separator parts,, buckets, and other equipment. To rinse out all traces of the soap boiling water must be sucked through the machine, at least 1 gallon being passed through each set of teat cups, and this must be done immediately after using the soapy water. If the rinse water is not hot enough, soap will be deposited in various parts ■ of the machine and will spoil the flavour of the milk or cream. Care must be taken. to avoid the use of soap containing carbolic or other pronounced perfumes; good, plain, laundry bar soap .is preferable to home-made soap, which is apt to produce deposits in the rubberware. Soap powder at the rate of 1 or 2 teaspoonfuls to 4 gallons of water may also be used, but some brands of soap powder appear prone to produce white deposits in the rubberware. A good plan is to prepare some soap jelly daily by pouring boiling water on soap Bakes; this will be found to dissolve readily in boiling water. next day. In some districts limited supplies of other substitutes for caustic soda, such as soda ash, trisodium phosphate, or metasilicate of soda, may be available.

Satisfactory results may be obtained by using these alkalis more liberally than caustic, at the rate of a tablespoonful or' more to 4 gallons of water. The best substitute is a mixture made up under various trade names and containing about 75 per cent, of soda ash and 10 to 15 per cent, each of metasilicate of soda , and trisodium phosphate. Soda ash mixtures should be used more liberally than caustic, 2 to 4 teaspoonfuls to 4 gallons of water. For softening the hard 'water on some farms the soda ash mixture is' particularly recommended, but it must be added before putting in the soap, at.the rate of a teaspoonful to 4 gallons of water. Another alternative alkali which, may be available is caustic potash; it should be used in precisely the same way as caustic soda. These methods have been used to a limited extent in the past, and have given good results when care was taken. - . .

IBOOK REVIEW!

“The Farms of Great Britain”: H. G. Sanders and G. Eley HTHIS outline of the farm manage- -®- ment methods of' 11 farms given in “The Farms of Great Britain” is probably the best treatment of the subject since Sir Daniel Hall’s “Pilgrimage of British Farming.” Not only does it give the story -of. how farmers adjusted farm management methods to meet the wartime food demands, but it provides an excellent study of the effect of soil, climatic, and marketing factors on production methods. ■ The book summarises a 8.8. C. series of discussions on “This is My Farm.” Eleven different but typical farmingareas of Britain were chosen for inquiry , and from each a well-known farmer was selected to discuss the reasons for his particular system of farm management. Although British conditions are different from those in this country, New Zealand readers will find much to interest them in this book. For each farm particulars are given of the gross receipts per acre and per man. The per acre receipts vary from 30s. for an extensive sheep farm ,on the Scottish Borders to £4O for an arable farm on the Lincolnshire silts. Three farms have gross receipts of £lO an acre, three £2O, two £25, and two £3O or more. The gross receipts per man employed (out of which, of course, have to be met the necessary proportions of rent and working expenses) vary from ' £6OO to £1200; seven of the farms are in the £6OO group. - . > C . —P.W.S. Crosby Lockwood and Son, Ltd., 12s. 6d. net. x \ - j "