Once the jar is opened the manner in which it was processed - BWB or pressure canned - becomes irrelevant.

The shelf life is determined primarily by the particular food and how it was prepared (the recipe used) rather than how it is processed. Temperature maintained in the fridge also is important. Below 40 gives a longer storage life than above 40.

The lower the pH of the jar contents the longer they can be stored in the fridge. So for example, sugared fruit jams last longer (1 year) than low sugar jams (4-6 mos.) or pickles, pickles will have a longer shelf life (3 mos.) than say salsa or tomato juice, tomato products (1-2 weeks) will last longer than green beans or other vegetables, (days) etc. It is the pH, the acidity of the food in the jar, that counts.

But pickles made with straight vinegar will have a longer shelf life than those made with 1/2 water and 1/2 vinegar because of their pH.

OK?

Dave

Everything Dave said. There are some few other factors as well. For example, once opened over time a sugared preserve may crystallize due to the evaporative effect of air. The jam is still "edible" but not very appealing.

For that reason it's important to keep track of how long a batch stays on your shelf to calculate amount of canning in a season and also optimal jar sizes so that products get used up in a timely manner once opened. That may mean more initial expense for smaller jars and additional lids but in the long-term less waste.

Carol

Awesome info thank you.