Place a large pot of boiling water over high heat. Make sure the pot is about halfway filled with water. Gently drop fresh peaches into the water and cook for about a minute. Carefully remove them from the water using a slotted spoon and cool them immediately under cold running water to stop the cooking process. Remove the pot filled with water from the heat. Peel the peaches, and cut them in half, remove the kernel, then slice them into 1 cm (1/2 inch) chunks.
cook the peach jam
Add peaches, sugar, vanilla paste, and agar to a large pot. Stir to combine, and place over medium-high heat. Bring to a boil, then lower the heat and simmer for 30 - 35 minutes, or until the jam is thickened. Occasionally stir to combine, and using a ladle remove any foam that forms on top while cooking.
can the jam
Clean four medium-size (approx. 320ml) canning jars. Preheat the oven to 100°C / 210°F. Place the jars along with the lids on a baking sheet. Place in the oven for 15 minutes. Remove the jam from the heat, stir, and fill the hot jars (be careful) with the peach jam. Tightly close with a lid. Using a kitchen towel, wrap the jars tightly and let them cool to room temperature slowly. Keep the canned peach jam in a dark, cold space for up to a year.