Now to why I originally logged on.
While watching Dr. Oz, I learned something about lemon juice and why our jelly's and jam's may not set right. Check your label and you might see as I just did that my store brand contains water AND lemon juice.
Some contain Citric Acid too.
Seems to me if I'm adding an extra teaspoon of water or something else the reaction may not be the degree of acidity I need to set my jams/jellies.
I also think using a liquid setting product instead of a dry when the recipe calls for dry may also be another reason for runny jellies and jams.
My plan from now on is to either use real lemons and squeeze my own juice or read the label and be sure what I'm using has no added water or citric acid, but is 100% lemon juice.
Am I right in thinking this could be the problem with bad sets?
Dr. OZ showed an experiment where they put lots of baking soda in water and then poured in some store bought lemon juice. If there is little reaction, it's because there is little lemon juice in your product.
Lemon juice can be frozen in ice cube trays it was said.