What is challenge testing?

A powerful tool to help support microbial safety, validate shelf-life, and strengthen your food safety systems.

Challenge testing involves deliberately inoculating a food product with a microorganism of concern under controlled conditions. The product is then monitored to see if the organism grows, survives, or dies off. The results provide critical insight into whether the food remains safe and within regulatory limits.

These studies are commonly applied to pathogens such as Listeria monocytogenes, Bacillus cereus, and Staphylococcus aureus, as well as spoilage organisms like lactic acid bacteria, moulds, and yeasts.

Types of challenge testing we offer

We offer two core types of microbiological challenge testing, tailored to your needs:

• Growth potential testing: Determines whether the food supports microbial growth and sets maximum acceptable limits at the end of shelf-life
• Growth rate testing: Evaluates how environmental conditions (e.g. pH, temperature, water activity) affect microbial growth over time

These tests help manufacturers understand microbial risks specific to their product and production process.

Challenge testing and shelf-life assessment

Challenge testing plays an important role in determining the shelf-life of food products. By simulating contamination and monitoring microbial behaviour, we provide valuable insight into potential spoilage or safety concerns.

These results feed into our broader consultancy-led shelf-life validation service, where shelf-life is determined based on multiple parameters, including sensory, chemical, and microbiological factors.