If you have never made jam before let me give a few little tips. Try to use a pot that has lots of room (very high sides) because there will be super hot splatters to deal with. Definitely invest in a digital thermometer and use it (made that mistake once and I unintentionally made fig candy). Don't get discouraged if it doesn't come out right. If it comes out a little runny then just tell people you made berry syrup instead, they will still be just as impressed, I promise. You need to become familiar with how jam feels and how you test to see when it is set, and the only way to do that is to try it.
Mixed Berry Jam
6 cups (780 grams) of mixed berries: Blackberries, Raspberries and Blueberries (Fresh or Frozen)
Juice from one lemon
1 cup sugar (I used Sucanat but feel free to use what you have)
1/2 cup *buckwheat honey
Start a boiling water bath if you plan on processing your jam. Since this recipe doesn't make that much jam you could always keep it in a container in the refrigerator and not worry about canning.
Place all the ingredients into a non-reactive pot and bring to a boil over medium to high heat. Keep the mixture at a rolling boil and stir occasionally so that the bottom doesn't burn. Heat the mixture until a thermometer reaches the set point at 220° F (You could perform a freezer test if you want as well). The mixture should be thick. When you spoon through the mixture it should separate so you can see the bottom of the pot and it should sheet off the spoon.
Sterilize your jars, ring and lids and get them ready on the counter. Spoon the hot jam into the jars, seal finger tip tight and process in a boiling water bath for 10 minutes. Set on the counter to cool and test the seals when they have cooled down.
*Buckwheat Honey: This recipe calls for buckwheat honey because I personally love it. The smell is...well lets not talk about what it smells like because if you never noticed it before you will once I say it, and then you will never be able to eat buckwheat honey again. You don't need to use it if you don't want to. You can either use another 1/2 cup of sugar or a different kind of honey. Everything about this recipe can be changed to suit your preference so please deviate if you want/need to.