Bring a large pot of water to a boil. Place the peaches into the water for 20 to 45 seconds. Using a slotted spoon, transfer the peaches to large bowl of cold water and ice (if available); allow them to cool for several minutes. Peel off the skin. Cut the peaches in half and remove the pits. Leave the peaches halved or cut each half into quarters. Place the peaches in a bowl, add the lemon juice, and stir well to prevent the fruit from darkening.

In a medium non-reactive pot, combine the sugar and water. Bring the liquid to a simmer and stir in the peaches. Return the liquid back to a simmer. Continue to simmer for 5 minutes.
Using a slotted spoon, pack the peaches tightly into hot, sterilized 500 mL jars. Cover them with the hot sugar syrup, leaving 1/2-inch of headspace. Run a rubber spatula gently between the peaches and the jar to release any trapped air bubbles. Top up with sugar syrup as required to maintain the headspace. Wipe the rims, put on the lids, and process the peaches in a water bath for 20 minutes.

Makes 4 or 5 500mL jars