I have been making blackberry jelly for several years as I have a huge blackberry patch. This year for some reason my jelly did not turn out. I used the dry pectin.. It is very frustrating.. I tried what the instructions told me also about what to do if it doesn't jell, that didn't work either.. So I can't answer your question.. but like others have said on here stick to what the recipe tells you to use and do it exactly as it says