Shelf Stability of RTE Meat Products Based on pH and Water Activity: Critical Limits
Fully cooked, RTE meats that are shelf-stable do not support growth of L. monocytogenes or S. aureus at room temperature. A combination of product pH and water activity in a HACCP plan will ensure shelf stability. Follow these steps to set Critical Limits for pH and water activity that will support shelf stability*:
- Select product category. Dried product includes beef jerky, beef strips, pemmican. Fermented product includes fermented summer sausage, salami, snack sticks – or products made with encapsulated organic acids.
- Measure product pH. [Determination of pH in Meat and Poultry Products, USDA/FSIS]
- Use the table (below) to establish the maximum Water Activity at the measured pH.
For example:
Beef strips – Dried product with pH of 5.8, or lower, has a maximum water activity of 0.85 for shelf stability.
Summer sausage – Fermented to pH 5.3, or lower, has a maximum water activity of 0.91 for shelf stability.
Product Category
Dried Product
Fermented Product
pH (maximum)
6.3
6.2
6.1
6.0
5.9
5.8
5.7
5.6
5.5
5.4
5.3
5.2
5.1
5.0
4.9
4.8
4.7 or lower
Water Activity (maximum)
0.80
0.80
0.80
0.80
0.85
0.85
0.85
0.85
0.85
0.85
0.91
0.91
0.92
0.93
0.96
0.96
0.96
*NOTE: Critical Limits for pH and water activity for use only with fully cooked, ready-to-eat products. Published research used to generate these Critical Limits is found on the bottom of this page.