Want to make a blackberry jelly that your friends and family will rave about? This recipe makes an exceptional jelly. This recipe is special. Natural pectin in apples is used to thicken the jelly rather than powdered pectin. The recipe and methods are inspired and adapted from this Blackberry Jelly Recipe

I've tried to provide enough details to give you first-time jelly success. I welcome and appreciate all comments and tips you may have.

Step 1: Ingredients and Equipment

Ingredients

12 cups (2.8 liters) blackberries
2 large tart apples. e.g. Granny Smith
1/2 cup (120 ml) water
1/2 cup (120 ml) sugar for each 1 cup (240 ml) of juice

Equipment:

jelly straining bag and stand
glass mason jars: 4 oz (125ml) or 8 oz (250ml) Ball Mason Jars Bernardin Jars
snap lids for jars (usually packaged with the jars)
screw bands for the jars (usually packaged with the jars)
ladle
candy thermometer
tongs
wooden spoon
2 cup (480 ml) measure
1/2 cup (120 ml) measure
1/4 cup (60 ml) measure
cooking pots

Step 2: Clean the Jars

You need to plan ahead to have sterilized jars ready for the canning step.

Start by planning how many jars you will need. The quantities in this recipe will yield about 32 oz (950 ml) of jelly. That will fill 4 x 8 oz (250 ml) jars. Or, 8 x 4 oz (125 ml) jars. I use a combination of jar sizes. Close friends and family get the bigger ones !

To sterilize, there are various techniques that are possible. I prefer the "wash-and-bake" method.

Clean the jars in the dishwasher. Or, hand wash and rinse. At a later time the jars will go into the oven for the final sterilization step.

Step 3: Prepare and Combine the Ingredients

Get out a large cooking pot around 6 quarts (6 liters) in volume.

Shred the 2 apples with either a food processor or grate them by hand.

Add the 12 cups (2.8 liters) blackberries and the shredded apple to the pot.

Add 1/2 cup (120 ml) of water.

Step 4: Cooking the Berries

Bring the mixture to a boil over medium heat.

Boil about 20 minutes, stirring occasionally. Towards the end of the cooking time I use a masher to grind the berries to the bottom of the pot. This will help to release the juice from the stubborn berries.

Step 5: Strain

In this step you will extract the juice from the mixture.

Remove from heat.

Set up the jelly stand with bag over top a receiving pot. Make sure the stand is stable. Use a ladle to transfer the hot mixture into the jelly bag. Allow the juice to flow into the receiving pot. Wait until the dripping mostly stops. I don't advise squeezing the bag to get more juice. I prefer the taste and texture of jelly when the bag is not squeezed.

At this point you can either continue to make the final product or you can store the juice in the refrigerator and complete the jelly at a later time.

Discard the leftover pulp in the jelly bag once it has cooled.

Step 6: Sterilize Jars and Snap Lids

It helps to complete this sterilization process before you proceed to the next cooking step.

Bake the jars in the oven at 250 deg F (120 deg C) for a minimum of 20 minutes.

Add the snap lids to a small pot and cover with water. Bring to a boil. Turn down the heat to simmer.

The jars and lids are now sterilized and ready for the canning step.

Step 7: Cooking the Strained Juice

Measure around 5 cups (1200 ml) of juice into a pot with high sides. A pot with volume around 4 quarts (4 liters) is well suited for cooking the juice. Note how much juice you added. The amount of sugar you add is proportional to the amount of juice.

Rapidly bring the juice to a boil.

Add 1/2 cup (120 ml) of sugar for each 1 cup (240 ml) of juice.

Now it is a matter of boiling until the jelly stage is reached. You want to have a fairly rigorous boil so the cook time is short. Low heat leads to longer cook times which can destroy the natural pectin making a runny jelly. The Medium setting on our electric stove top gives good results.

There are various ways to tell that your juice has reached jelly stage. Here is a guide describing 3 methods for determining when to stop cooking. 3 ways to know your jelly is done

Of the 3, my preferred method is the temperature test. A basic cooking thermometer seems to produce consistent results. As discussed in the guide, jelly temperature is 220 deg F (104.4 deg C) at sea level. As elevation from sea level increases, the jelly temperature decreases. In general, jelly temperature is 8 deg F (4.4 deg C) above the boiling point of water.

Caution with digital thermometers. Often, they are not accurate. You can test the accuracy by checking the boiling point of water. One digital thermometer that I tried indicated 209 deg F for the boiling point of water. The correct reading should have been 212 deg F for our sea level location. That is too inaccurate for jelly making.

If your thermometer has a clip, attach it to the pot. Don't allow the thermometer to touch the bottom of the pot or the temperature will read high.. Boil the mixture on medium until the temperature reaches jelly temperature, stirring occasionally. Typical cook times are 25-30 minutes.

During cooking I skim and remove the scum that forms on the side of the pot.

Remove from heat as soon as the jelly temperature is reached.

Step 8: Canning

Select one of the sterilized jars from the oven. I use a 1/4 cup (60 ml) measure to transfer the liquid into the jars. Fill jars to 1/4" (6 mm) from the top. Make sure the rim of the jar is clean. A piece of paper towel can be used to clean errant drips if needed. Take a lid from the boiling water, add to the jar, seal with one of the screw bands. Apply screw bands securely until fingertip tight.

Set the jar aside to cool to room temperature. In a few minutes you will likely hear a pop when a vacuum forms inside the jar and pulls in the snap lid. Don't worry if you don't hear a snap - often the snap lid will be pulled in without a sound.

Gelling can require some patience. Don't be alarmed if the jelly has not set an hour after you sealed the container. It takes time to gel, sometimes a couple of days.

Step 9: Labelling

A final step is to label your jars. The jars likely came with labels that you can write on with a sharpie pen. Or, you can make your own. I use an ink-jet printer to create custom labels.

I plan to make a separate Instructable describing how to make labels and will include PowerPoint templates for common snap lid sizes.

That's it. Enjoy this outstanding jelly !