Perhaps you've never thought of ground black pepper as an ingredient in strawberry jam, but this traditional French recipe will change your mind! The black pepper isn't evident on it's own in the finished the gym, but it does very nicely offset the sugar giving it balance. Along with the fresh mint, it makes a perfect companion to strawberries and sugar. The lemon juice should be enough for the jam to set, but you can also add pectin at the end if you prefer.
Wash, hull and halve or quarter strawberries depending on size. Place strawberries in a glass bowl. Add sugar. Zest both lemons and juice them. Add zest and juice the strawberries. Gently combine ingredients, cover bowl with parchment paper and refrigerate over night or a bare minimum of 12 hours. It's best to leave them for 24 hours.
Add strawberry mixture to to a large saucepan. Bring to a simmer over medium -high heat, frequently stirring gently, until the sugar has dissolved (approximately five minutes).
Remove from heat. Strain mixture through a fine mesh sieve, reserving fruit.
Return syrup to saucepan over high heat and bring to a hard boil. Continue to boil until temperature registers 220F on a candy thermometer.
Add reserved fruit, mint, black pepper and butter to the syrup. Continue to boil, stirring gently, for eight minutes. Remove from heat. Check for set by placing a small amount of the mixture on a saucer and placing in the freezer for a few minutes. If mixture gels, it is done. If not, return to a boil. Cook for one minute, remove from heat and check again.
Once jam has set, remove from heat and immediately fill prepared, hot jars. Run a knife or spatula around the inside of each jar to remove air bubbles. Carefully wipe the rims of each jar clean, place lids and tighten rings until "fingertip tight."
Process in water bath for 10 minutes. Remove to a clean dish towel out of direct sunlight. Allow to rest for 12 hours. Check jars for seal. Reprocess or refrigerate any jars that did not seal properly. Jam will keep in a call, dark covered for up to one year.