This jam is made with strawberries that were frozen, rather than fresh. I just like the texture better, my personal preference, however I encourage you to try making this with fresh berries.
This jam is sweet and tart and perfect for any use, not just on toast. It's a very soft jam and easily spreadable. I highly recommend this with a sharp goat cheese on garlicky crisps.
5 cups of jam sugar, though to be honest any sugar works just as well.
1/4 tsp butter
5 tbls balsamic vinegar
Place the strawberries in a large pot and bring to a boil over medium heat, stirring frequently.
Once the strawberries are boiling, add the sugar and stir until dissolved. The sugar tends to burn so make sure to stir well, scraping up the bottom of the pot. Bring to a boil again and then add the butter, which will keep the foam down.
Turn the heat down and simmer the jam for 40 minutes until thickened. Stir in the balsamic vinegar.
When the jars are dry but still hot, use a slotted spoon to fill the jars with the thickened berries leaving 3/4 inch of headspace to allow for pressure to build during the canning process.
Use the last jar for just remaining juice, to which you can add more balsamic vinegar for use as a salad dressing or for marinading meat, chicken, fish or vegetables.
Wipe the rims, set on the lids, and screw on the bands fingertip tight. Place the jars in the rack in the large pot and add enough water to cover the jars with about 3 inches of water. Cover and bring the pot to a boil, then to lower the heat to medium for 10 minutes. Remove the cover and after 5 minutes, remove the jars. Set them on a dish towel on the counter and let sit undisturbed for six hours.
Sometime during the first hour your lids will make a pop noise, signaling that they're sealed. After six hours press on the lids, they shouldn't move at all. If they push in, they're not sealed. Try again with a new lid. These will last stored in a cool dark place for up to a year, though with how this tastes I don't see how they would last a month! Refrigerate after you open the jar.