Effect of curd washing on composition, lactose metabolism, pH, and the growth of non-starter lactic acid bacteria in full-fat Cheddar cheese

Cheddar cheese was manufactured in triplicate from mid-lactation milk and analysed over a 270-day ripening period. The curd was washed in the cheese vat to give target levels of lactose plus lactic acid in cheese moisture (LLAMc) in the final cheese of 5.3 (control), 4.5, 4.3 and 3.9% (w/w); these values correspond to the expected LLAMc levels in non-washed cheeses made from milk with lactose levels of 4.8 (control), 4.6, 4.3 and 3.8% (w/w), respectively. Increasing curd washing from 0 to 33% of milk volume significantly reduced mean levels of total lactate and LLAMc over the ripening period. Conversely, it increased the mean cheese pH by ∼0.3–0.4 at times ≥ 90 days. The LLAMc was ∼1.0–1.6 units lower than predicted based on levels of milk lactose and curd washing. Otherwise, alteration of curd washing generally did not affect gross composition or microbiology of the cheese.