INGREDIENTS AND EQUIPMENT
- Blueberries - 5 pints (which is 10 cups or about 3.5 lbs.) preferably fresh but frozen, without syrup, works too.
- Lemon juice - either fresh squeezed or bottled, 1/4 cup.
- Water - 1/2 cup
- Sugar - about 4.5 cups of dry, granulated sugar.
- Jar funnel
- At least 1 large pot
- Large spoons and ladles
- Jars, lids and rings
Step 2 - How much fruit?
Jam can ONLY be made in rather small batches - about 6 cups at a time - like the directions on the pectin say, DO NOT increase the recipe or the jam won't set. It takes about 8 cups of raw, unprepared blueberries per batch.
Step 3 - Wash the jars and lids
Now is a good time to get the jars ready so you won't be rushed later. The dishwasher is fine for the jars, the water bath processing will sterilize them as well as the contents. Leave the jars in the dishwasher on heated dry until you are ready to use them. Keeping them hot will prevent the jars from breaking when you fill them with the hot jam.
Step 4 - Wash the berries and sort
Wash the fruit in a colander of plain cold water. Pick out and remove any bits of stems, leaves, and soft or mushy berries.
Step 5 - Crush the berries
You can either do one layer at a time in a pan or bowl using a potato masher or you can be lazy like me and use a handy chopper. Either way if you start with 10 pints of berries you will end up with about 6.5 cups of crushed blueberries.
Step 6 - Measure out the sweetener
The precise measurements are found in directions inside each and every box of pectin sold. Every brand has directions inside. I made regular jam so I bought regular pectin and used 7 cups of sugar. There are different types...low sugar, no sugar, lower sugar, natural. Depending on what type of jam you are making you will need to use a different amount of sugar and type of pectin.
Step 7 - Mix the dry pectin with about 1/4 cup of sugar
Keep this separate from the rest of the sugar. I added about 20% more pectin from another box just to make sure my jam was thick. I did not want it to be runny.
Step 8 - Mix the blueberries with the pectin and cook to a full boil
Stir the pectin, lemon juice and water into the blueberries and put the mix in a big pot on the stove over medium to high heat. Stir often to prevent burning. It should take about 5 to 10 minutes to get it to a full boil.
Step 9 - Add the remaining sugar and bring to a boil
When the berry-pectin mix has reached a full boil, add the rest of the sugar (about 4 cups of sugar per 6 cup batch of blueberries) and then bring it back to a boil and boil hard for 1 minute.
Step 10 - Fill the jars and put the lids and rings on
Fill them to within 1/4 inch of the top, wipe any spilled jam off the top, seat the lid and tighten the ring around them. Then put them into the boiling water canner. (I just used a big pot I have...might ask for a canner for Christmas!)
Step 11 - Process the jars in the boiling water bath
Keep the jars covered with at least 1 inch of water. Keep the water boiling for 5 minutes. (I did a little longer. It was more like 7 minutes before I started pulling them out and maybe 10 for the last jars.)
Step 12 - Remove and cool the jars - Done!
Lift the jars out of the water and let them cool without touching or bumping them in a draft-free place (usually takes overnight). Once they are cooled, they're ready to store. They last up to 12 months but I read that after 6 to 8 months they may get darker and a little runny. They are still safe to eat, but the flavor and texture aren't as good. So eat them in the first 6 months after you prepare them.