Fowlers Vacola Preserving Lids

When preserving, lids are placed on the bottle on top of the preserving ring and secured with a clip. When first put on the bottle, the lid appears convex, which will change to concave after processing, indicating the vacuum seal has formed. 
Stainless Steel lids provide a ‘longer life’ alternative and should be used for all high acid preserves, including pineapple and pickles.