I have... I used recipes from the Ball canning book. I didn't do strawberry, I did blackberry tamarind, plum ginger etc. You'll have a lot of luck if you combine high pectin with low, but the blackberry (low pectin) jams turned out a really delicious preserves... though definitely not a jelly. You can also look up recipes for homemade pectin out of sour apples.
That said, you need to cook the jam. Really really cook it until it gets "sparkly." This will be much longer than you think. You'll see it start to shine well before it gets really sparkly & want to take it off, but wait it out! You'll know super sparkly when you see it! It's like watching fireworks!
I haven't tried this recipe, but I found it via google... a candy thermometer sounds like a good idea to me!!! I made cooked jam before I discovered the usefullness of my meat thermometer & started temping
everything. I really need a candy one too, apparently!
Old Fashioned Whole Berry Preserves
This recipe comes from Rudd's Farm, in Greensboro, NC (
www.ruddfarm.com).
6 cups fresh small fully ripe whole strawberries,washed and hulled
Boiling water to cover strawberries
1/2 cup lemon juice
6 cups sugar, divided
In a large saucepan, cover berries with boiling water; let stand 3 minutes to soften. Drain water and discard. Combine berries and 3 cups of the sugar in a 6 to 8 quart saucepan. Bring to a boil over high heat, stirring constantly. Reduce heat; continue to boil slowly on medium heat 8 minutes, stirring constantly. Add remaining 3 cups sugar and lemon juice. Boil 10 minutes more, stirring constantly. Using a candy thermometer, bring to the gelling stage of 220-225 degrees. Remove from heat. Stir and skim off foam with metal spoon for 2 minutes. Pour jam into shallow baking dish to cool completely. When cold, put in sterilized jars and freeze or process.
http://www.ncstrawberry.org/docs/Jams.htm