(a) Quality control tests shall be made on samples as often as necessary to determine the shelf-life and stability of the finished product. Routine analyses shall be made on raw materials and finished product to assure satisfactory composition, shelf-life and stability.

(b) Frequency of sampling—(1) Microbiological. Samples of raw milk for testing shall be taken as prescribed in §58.135. Representative samples shall be taken of finished cottage cheese and from each lot or batch of product used as an ingredient. For keeping quality tests representative samples shall be taken of finished cottage cheese;

(2) Chemical—(i) Milkfat and Moisture. Representative samples shall be taken of cottage cheese; dry cottage cheese shall be tested for moisture only.

(ii) pH. Representative samples shall be taken of finished cottage cheese.

(c) Test methods—(1) Microbiological. Microbiological determinations shall be made for coliform, psychrotrophic and yeasts and molds. These tests shall be made in accordance with the methods described in the latest edition of Standard Methods for the Examination of Dairy Products, published by the American Public Health Association.

(2) Chemical. Chemical analysis shall be made in accordance with the methods described in the latest edition of Official Methods of Analysis of the Association of Official Analytical Chemists, published by the Association of Official Analytical Chemists, the latest edition of Standard Methods for the Examination of Dairy Products, or by other methods giving equivalent results.