Quote: Originally posted by Aderynglas on 22/12/2016
Mmmm
We use hot water here, if a jam jar lid refuses to budge.
Hot water on lid causes the metal to expand and the air inside to expand lessening the vacuum effect - result, an easy to open lid!
If there is a vacuum inside the jar, then there should not be any air in it to expand. If there is air inside, it may be better for your health to return the jar to the supplier.