When Curdling Doesn’t Go as Planned
The curdling process relies on proper acidification and controlled use of starter cultures and rennet. If the milk is not acidified correctly, or if cultures or rennet are added in the wrong amounts, curd formation may be weak, slow, or uneven. In some cases, curds may not form at all.
Temperature also plays a critical role. If the milk is too warm or too cold during curdling, bacterial activity and protein coagulation are disrupted, leading to inconsistent curds and poor yield.
Pasteurization Failures and Food Safety Risks
Proper pasteurization is non-negotiable in cottage cheese production. Milk that is inadequately pasteurized may contain harmful pathogens such as Listeria, Salmonella, or E. coli, posing serious food safety risks. Beyond health concerns, contamination at this stage often leads to spoilage, recalls, and reputational damage.
Texture Problems: Too Firm, Too Soft, or Rubber-Like
Curd texture is highly sensitive to cooking time, temperature, and enzyme levels. Curds that are cooked at excessively high temperatures or for too long tend to become overly firm or rubbery. On the other hand, insufficient heating leaves curds too soft and fragile, making them difficult to handle and prone to breaking.
Overuse of rennet can worsen these problems by causing curds to set too quickly and tightly, resulting in a dense, undesirable texture.
Flavour Defects and Spoilage Issues
Bitterness in cottage cheese is often a sign of improper fermentation, contaminated cultures, or low-quality rennet. A slimy or ropy texture typically points to contamination by spoilage bacteria such as Pseudomonas, or inadequate washing of the curds.
If curds are not drained correctly, excess moisture remains in the cheese, leading to a watery, unstable product that spoils more rapidly.
Salt also plays a dual role in flavour and preservation. Too little salt results in bland taste and reduced shelf life, while too much salt can overpower flavour and damage texture.
Washing and Handling Errors
Washing the curds is a defining step in cottage cheese production. If washing is done poorly, curds may retain too much acidity or unwanted bacteria. This can result in an overly sour product, texture defects, and increased spoilage risk.
Ingredient and Sourcing Challenges
Everything starts with the milk. Poor-quality milk leads to weak curds, off-flavours, and shortened shelf life. Seasonal variations in milk composition—especially changes in fat and protein levels—can further complicate consistency if formulations are not adjusted.
Milk containing antibiotics is particularly problematic, as antibiotics suppress the growth of starter cultures, preventing proper fermentation and curd development.
Using old or contaminated starter cultures introduces another risk, often causing erratic fermentation and flavour defects. Non-homogenized milk can also result in uneven fat distribution, leading to inconsistent curd formation.
Even water quality matters. Contaminated or poorly filtered water used for washing curds or cleaning equipment can introduce bacteria or chemical residues that affect safety and taste.
Hygiene and Equipment Risks
Unclean or poorly maintained equipment is a major source of contamination in cottage cheese manufacturing. Inadequate sanitation allows harmful bacteria to enter the process, leading to spoilage, safety concerns, and regulatory violations.
Storage, Packaging, and Cold Chain Failures
Cottage cheese is highly sensitive to storage conditions. If stored at elevated temperatures, bacterial growth accelerates and spoilage occurs quickly. Freezing, while preventing spoilage, damages the curd structure and results in a grainy texture once thawed.
Improper packaging that allows air, light, or contaminants to enter reduces shelf life and encourages mold growth. Poor sealing techniques further increase the risk of moisture loss, oxidation, and contamination. Exposure to light can also degrade vitamins, particularly riboflavin, and create off-flavours.
Transportation is another critical point. Breaks in the cold chain or prolonged delivery times can compromise product quality before it even reaches the retailer.
Regulatory and Compliance Pitfalls
Failure to comply with food safety regulations can result in product recalls, fines, and loss of consumer trust. In South Africa, incorrect labeling—such as missing allergens, inaccurate ingredient lists, or wrong nutritional information—carries serious legal and commercial consequences.
Using expired raw materials or sourcing from unlicensed suppliers increases the likelihood of contamination and regulatory non-compliance. As production scales up, manufacturers face additional challenges, including updated HACCP plans, stricter hygiene controls, and increased regulatory oversight.
Poor traceability systems further compound risk, making it difficult to identify and contain problems when they arise. Environmental non-compliance, particularly in waste disposal and water use, can also lead to fines and reputational damage.
Controlling Risk Through Good Manufacturing Practice
Cottage cheese manufacturing leaves little room for error. From milk intake to curd washing, packaging, and distribution, every step must be tightly controlled. By maintaining high-quality raw materials, strict hygiene, precise process control, and full regulatory compliance, manufacturers can minimise risks and consistently deliver safe, fresh, and high-quality cottage cheese to the market.
