@Njoki ..Maybe your jam recipe was not right and the recipes are not balanced,,, as its a school work then you should search the web or read fruit processing books from your library for standardized jam recipes that you can try. Your instructor could be your immediate source of guidance,,
As a student its best to cultivate initiative of searching for solutions by yourself from wide venues like library and the web...
Science degree aspirants that lacks that virtue of initiative would find their future difficult as most science problems requires focused thought and independent thinking, plus the courage and tenacity to persist in solving out the problem,
, If you thrive on asking for help every time you had a small problem you will not able cultivate good research habits that will be useful to you in the future career.