CURSO
04 · APPLIED MICROBIOLOGY
Microbial growth and time/temperature control
Microorganisms need favourable conditions to multiply. Food handlers must pay particular attention to nutrients, moisture, temperature, time and, depending on the microorganism, oxygen availability.
The time + temperature combination
There is no single universal temperature suitable for all foods. Legal conditions depend on the product, the process and the applicable regulations. Manufacturer instructions and the conditions established in the food safety management system must also be followed.
| Situation | Practical criterion |
|---|---|
| Refrigeration | Keep each food within its legally required temperature or the temperature indicated on its labelling/food safety management system. |
| Frozen foods | As a legal reference for many products in retail: ≤ −18 °C. |
| Refrigerated prepared foods | ≤ 4 °C if shelf life exceeds 24 h; ≤ 8 °C if it is less than 24 h, subject to applicable justified conditions. |
| Hot prepared foods | Keep at ≥ 63 °C when maintained hot under the applicable requirements. |
| Danger zone | Avoid unnecessarily keeping perishable foods at room temperature. |
DO NOT GENERALISE
The old criterion “all refrigerated foods at 0–5 °C” should not be used as a universal legal rule. In 2026, the specific temperature requirements for the product and applicable regulations must be consulted.
The old criterion “all refrigerated foods at 0–5 °C” should not be used as a universal legal rule. In 2026, the specific temperature requirements for the product and applicable regulations must be consulted.
Regulatory basis / source: Royal Decree 1021/2022, Article 4; Royal Decree 1086/2020, Article 30, and manufacturer's storage conditions.