TAKING COMPOSITE MILK SAMPLES.

New Zealand Mail, Issue 1510, 7 February 1901, Page 51

TAKING COMPOSITE MILK SAMPLES.

The modern creamery and cheese factory uses the Babcock test for determining the richness of the milk delivered by each patron. The most common and satisfactory method of paying for the milk according to its test is to take a small sample of each lot of milk every day, pour this into a covered glass jar containing a small amount of some preservative and at the end of the week or 10 days test this composite sample. The essential features of the process are given in the following directions : Provide a pint or quart jar or bottle for each patron. Label each bottle with a number, giving the same number to a patron on the milk recording sheet. Composite test sample bottles made for this purpose with a tin cover and numbered brass tag wired to the neck of each bottle can be obtained of creamery supp'v firms. These sample bottle should be placed on shelves within ea?y reach of the weigh can, and protected from the light. A preservative is put into each clean bottle to keep the milk from souring, until testing day. Pulverized potassium bichromate, corrosive sublimate, borax or preserve line can for this purpose. Some of these preservatives are put up in tablet form, each tablet containing the necessary amount to use in ohe sample. After each lot of milk is poured into- the factory weigh can, a small amount of it is dipped from the can and poured into the proper sample bottle. These samples are usually taken with a small 1-qz tin dinner, a sampling tube, or from a drip in the conductor snout.

Each lot of milk sampled must be sweet, containing no clots, lumps of curdled 'milk, or small butter granules. The sample shogld he taken just as soon as the milk is weighed, and while it is evenly mixed. Continue adding a sample of each patron’s milk to his particular jar every time he delivers milk for a week or 10 days, then test this composite sample. The composite sample jars should lie kept covered to prevent loss by evaporation, and in a cool, dark place. Every time a new portion of milk is added to th© jar it should be given a horizontal rotary motion to mix the cream already formed in the jar with the milk, and to rinse off the cream sticking to its side. Unless this is don© every time fresh portions of milk are added to the jar the cream on tire milk becomes lumpy and sticks in patches to the side of the jar, thus making it nearly impossible to evenly distribute this cream through the entire sample* Composite samples having patches of dried! cream on the inside of the jar are the result of carelessness or ignorance on the part of the operator. The test of the composite sample takes the place of a separate daily test and gives accurate information regarding the average quality of the milk delivered by each patron during the period of sampling. The weight of butter fat which each patron brought to the factory in his milk during this time is obtained by muJtiplyng the total weght of milk delivered during the sampling period by the test of the composite sample, divided by 100.