During cheese manufacture and ripening: (B) Lactose fermentation occurs first and fastest (within hours to a few days during cheese manufacture); followed by (A) Proteolysis (breakdown of caseins by rennet and starter peptidases occurring continuously over weeks); followed by (C) Lipolysis / Free fatty acid production; and lastly (D) Alcohol and secondary volatile aroma compound development over months of prolonged maturation. Thus, the sequence is B, A, C, D.

In cheese making, cheese blocks are waxed by dipping into molten cheese wax / liquid paraffin maintained at $104\text{--}121^\circ\text{C}$ ($220\text{--}250^\circ\text{F}$) for 5 to 6 seconds. This high temperature instantly sterilizes the surface mold spores, flashes off any surface moisture, and deposits a thin, flexible, airtight protective barrier.

Traditional calf rennet extracted from the fourth stomach (abomasum) of unweaned suckling calves consists predominantly of chymosin (also known as rennin, approximately 80-90%) along with a small amount of bovine pepsin (10-20%). Chymosin specifically hydrolyzes the peptide bond between Phenylalanine-105 and Methionine-106 of $\kappa$-casein.

Whey protein denaturation and steric hindrance of chymosin:
(A), (C), (D) Temperatures below $65^\circ\text{C}$ do not denature whey proteins.
(B) When milk is heated above $70^\circ\text{C}$ (e.g., $72\text{--}75^\circ\text{C}$ for prolonged holding), the major whey protein $\beta$-lactoglobulin denatures, exposing its reactive free sulfhydryl ($-SH$) group at Cys121. It forms a covalent disulfide-linked complex with $\kappa$-casein ($\beta\text{-Lg}\text{--}\kappa\text{-casein}$ complex) on the micellar surface. This complex sterically hinders chymosin from reaching the Phe105-Met106 cleavage site and shifts soluble ionic calcium into insoluble forms, heavily prolonging or completely preventing rennet coagulation.