Calling experienced jam makers! I recently learned how to make jam in a cooking class and was warned against doubling recipes. I seem to have forgotten the warning yesterday when I made Strawberry Rhubarb Jam. The jam tastes and looks great, but I hope it will keep on the shelf. I used 2 1/2 lbs. of Rhubarb, 3 lbs. of Strawberries, 4 cups of sugar and 1/4 cup of bottled lemon juice. This batch filled 7 1/2 pt. jars. I followed all the sterilizing and processing rules. What do you think?