3507.10.00.00 - Rennet and concentrates thereof

This HTS category, 3507.10.00.00, specifically covers rennet and its concentrated forms. Rennet is a complex mixture of enzymes, primarily chymosin, produced in the stomach of young ruminant animals. Its primary industrial use is in cheesemaking, where it coagulates milk protein, initiating the curdling process. Concentrates are preparations that have undergone processes to increase the enzyme activity per unit volume, making them more potent and efficient for commercial applications.

This classification distinguishes itself from its sibling category, 3507.90, which encompasses all other prepared enzymes not specifically listed elsewhere within the 3507 chapter. While both categories deal with enzymes, 3507.10.00.00 is narrowly focused on the specific enzyme complex known as rennet, due to its distinct properties and singular primary application in the dairy industry. Category 3507.90 would include other digestive enzymes, industrial enzymes used in baking, brewing, or textiles, and any other enzyme preparations not classified under the more specific subheadings of 3507.

As this is a leaf node within the HTS, there are no further subcategories under 3507.10.00.00. Therefore, the classification relies on the specific identification of the product as rennet or a rennet concentrate. Key classification criteria would include the presence of chymosin as the primary active enzyme, its origin (natural or biotechnologically produced), and its intended use in the coagulation of milk for cheese production. Products that contain rennet as a component but are primarily something else, such as a pre-made cheese culture mix, would be classified elsewhere based on their principal character.