How to find a source of contamination in a batch process?

Question

I've heard that when producing milk, they collect it from several different farms and mix it together. How do you stipulate in the contract that if a milk source is contaminated that producer is penalized

Answer 1

In any kind of batch processing like milk or grain, each batch that is co-mingled must be tested before mixing it in. If not the whole thing could be spoiled. If any batch tests bad it should not be picked up.

Answer 2

Dairies have to test their own milk.  The records are to be given to the processors.  If a dairy sends bad milk they are required to buy back all the milk that is now contaminated.  

Start with the Code of Federal Regulations, Title 21, Section 131 and read from there.