Blackberry Jam


Making preserves is SO MUCH EASIER than everyone thinks. My total in-kitchen time was under 45 minutes for this project. Below I'll explain why you need to place jelly jars in boiling water and why you should add this white powdery substance to your fresh blackberries. Knowing the technical side of canning will make the process more seamless and give an understanding of the WHY behind the steps in the recipe instead of simply following blindly. Enjoy!

First, some Technical Tips:


  1. Always sanitize your jars before getting started. The whole purpose of canning is to rid the jar of bacteria, which can spoil your jars within a couple of months. We like them to last for up to a year, so less bacteria equals longer shelf life!
  2. Next, Pectin. Pectin is a natural chemical that is found in all fruits (higher in some than others) and is what forms the “gel” in jelly when heated to a high temperature. In the old days, back when my grandmother made jam, she did not use any added pectin. When you boil fruit, pectin is automatically released and the longer you boil the more “jelled” the fruit becomes. I chose to use a purchased pectin made by Ball. Powdered pectin is a natural product derived from apples. When you boil fruits, they tend to lose both taste and vitamin content. Adding pre-made pectin will reduce required boiling time while salvaging taste and nutrition.
  3. Selecting the pan that you boil your fruit in is important! Reactive pots, such as aluminum, can leach metallic elements into highly acidic ingredients like fruits for jams and tomatoes for making marinara. Your best bet is to use a coated cast iron such as Le Creuset or a coated stainless, like Calphalon
  4. Boil your jars! Once your recipe is made and filled into the jars you are going to seal them with very little tension “fingertip tight”. You want the excess oxygen in jars to have room to escape. You will then boil the jars in water filled to 3 inches above the top for at least 10 minutes. The high temperature of the boiling water is going to prevent natural spoilage by destroying food contaminants and removing air from the jars. As they cool, a vacuum seal forms and allows the jam to sit preserved at room temperature for up to 12 months. If you are going to use within a month then you can skip this step and place jars of jam directly in fridge! 


Look for more tips in bold throughout the recipe!


This time I used blackberries instead of figs because they were on sale at Costco. Also, my fig tree dropped all its fruit with the first crazy weather day in Charleston, where the temperature went from 74 degrees in the afternoon to right at 32 degrees freezing overnight. My figs were shocked but luckily the tangerine tree is sweetening from the cold by the minute!


For this recipe you will need:

1. A large canning pot
2. A rack to sit in bottom of canning pot
3. 10 mason jars with lids
4. 1 large non-reactive pot
5. 1 small bowl
6. Funnel
7. Tongs



Before you begin, make sure you have a large stock pot with some sort of rack at the bottom. You don’t want the jars on the bottom of the pot but floating nicely in the middle surrounded by boiling water. Turn the burner on first so that it is boiling and ready to go when you finish cooking your blackberry mixture.


Start with 9 cups of uncrushed blackberries, 4-5 cups when crushed. You will also need ¼ cup fresh lemon juice, 6 cups of sugar, and 8 tablespoons of pectin. Again, this recipe is for regular pectin, not sugar-free.


Crush your blackberries in your non-reactive pot and add lemon juice. You always need something acidic to make jam, such as lemon juice. I always add fresh lemon juice, but a lot of people say that bottled has a higher acid content and makes for a more stable jam. I personally have never had stability problems and I like the taste of fresh lemons so that is what you will find in this recipe.



In the small bowl mix the 8 tbs. of pectin with ¼ cup of the sugar. This is to stabilize the pectin as it boils. Then sprinkle over the blackberry/lemon mixture. Set the remaining sugar aside, you will add this in a minute.


Bring your blackberry mixture to a boil on the stove with the heat on high. Not a simmer, but a full rolling boil that can not be stopped by stirring. Use a wooden or rubber spoon, not a reactive metal spoon, no metallic taste here! 


Once the blackberries are boiling, stir in the remaining sugar and bring back to a full boil for two minutes, stirring often. This is what activates that pectin! 



Turn off burner and make sure your jars are dry and ready to go. Place funnel on jar and add cooked blackberry jelly to 1/4inch from top of jar. Center lid on jar then screw on band until just fingertip tight. 

They are ready to go in the canner! 




Place jars in the boiling water. My rack will only hold 5 at a time so I did this in two batches.

Let jars boil for 10 minutes at sea level, more if you are at any kind of altitude. You want all of the jars rid of bacteria. 


To take them out I used jar clamps, which you can buy on Amazon for under $10. I have used grill tongs in the past which worked great too. 


Once you remove the jars, you want to let them sit in the same place for 12 hours without being disturbed. Place them on a towel in a low traffic area in your kitchen and allow to sit overnight. As the jars cool you will hear the popping noise of the jars, which is how you know the canning process worked and they are completely vacuum sealed. After a couple of hours of cooling you can touch the top of the jar and if it doesn’t pop up and down then you know it worked.


Now you have 10 8oz. jars of blackberry jam! Barely any cooking and only 2 bowls and a spoon to clean up! Easier than you can imagine. Also, this recipe can be used with any high acid fruits, such as strawberries and raspberries. I hope you enjoy!