As you lift jars out of the canner after processing, there often is water trapped on top of the lids. It is tempting to want to tilt the jars to drain that water off.
Don’t do it.
Tilting the jar could cause liquid and particles to seep between the lid and the jar rim, breaking the vacuum seal or preventing it from ever forming. Instead, lift the jars straight up and place upright on a towel or rack.
Don’t worry about water on top of the jars. It will evaporate during cooling. Avoid touching the lids while the seal is being formed.
To prevent mineral residue on the jars and lids, add vinegar to the canner to help neutralize hard water. Wipe jars with vinegar when completely cool, if needed.