Easy! Fill the pan with water, place it on the gas-stove.
Place the OPEN jar with salsa inside. The water level should be lower than a jar. Heat the water, but don't let it boil. When the jar with salsa gets hot, take it out and lock it.
The 2nd way is to take salsa and take it to almost boiling condition and put it in prepared hot jar. Then lock it.
When it cools, it will be safely Vacuum sealed.
Place the OPEN jar with salsa inside. The water level should be lower than a jar. Heat the water, but don't let it boil. When the jar with salsa gets hot, take it out and lock it.
The 2nd way is to take salsa and take it to almost boiling condition and put it in prepared hot jar. Then lock it.
When it cools, it will be safely Vacuum sealed.