Why are our RTD cans leaking, and what can liner do we need for lower pH products with salt?

Salt is highly corrosive to cans and a common cause of leaks, even when pH is above 3.0. Your canner may have incorrectly advised that liner isn't needed above pH 3—this guidance doesn't account for salt content or other corrosive compounds.

**Diagnosis and testing:** - Request a **BCT (can liner) test** from your canner to identify the exact liner type currently in use and whether it's appropriate - Conduct a **physical liquid compatibility test** to confirm the product won't corrode the liner - Check for corrosion occurring from inside the can (liner failure) or outside (residue on the exterior causing inward corrosion) - Verify sulphate levels in your recipe, as these also affect corrosion risk

**Liner recommendations:** - **Epoxy wine can liners** are generally the strongest option, though members have seen failures even with these when salt is present - Members report **Ardagh cans** performing better than **Ball cans** for corrosive products, though this may be liner-dependent rather than manufacturer-dependent

**Key considerations:** - Even minimum salt levels in the recipe can cause problems; consider **reformulation (removing or reducing salt)** if liner upgrades don't resolve the issue - This is described as "a minefield"—close collaboration with your canner and physical testing is essential before scaling production - Have your canner revisit their liner recommendation given the presence of salt in your recipe.