How to Can Peaches
To can peaches, start by blanching them and cutting them into quarters. Then, set the peaches aside, and make a simple syrup by dissolving sugar in boiling water. Next, simmer the quartered peaches in the syrup for 5 minutes before spooning them into sterilized canning jars. Once you've done that, fill each can with more of the syrup, leaving 1/2 inch of space at the top. Finally, seal the jars and can them using a canner.
Select your peaches. Freestone peaches are peaches where the flesh removes easily from the pit. These are the easiest peaches to can. Freestone peaches are the peaches most commonly found in grocery stores and markets. Keep in mind that it takes about 5 large peaches to fill 1 quart jar. Place the peaches in a bowl. Run the peaches and bowl under cold water. Blanch peaches in boiling hot water. Blanching peaches makes it easier to peel the peaches and stops the enzymes from degrading the flavor during storage. To do this, fill a pot with water and bring it to a boil. Put the peaches in the boiling water and make sure that they are submerged. Leave the peaches in the water for 40 seconds. If the peaches are slightly under-ripened, leave them in the boiling water for 1 minute. Quarter the peaches. Place the blanched peaches on a cutting board and use a knife to cut them in quarters. Throw away the pits. Pour ¼ cup of lemon juice onto the peaches. The lemon juice will keep the peaches from browning. Fill a pot with water. While heating the water, add sugar slowly. For light syrup, boil 6 cups of water and 2 cups of sugar. This will yield 7 cups of syrup. For medium syrup, boil 6 cups of water and 3 cups of sugar. This will yield 6 ½ cups of syrup. For heavy syrup, boil 6 cups of water and 4 cups of sugar. This will yield 7 cups of syrup. Stir the mixture slowly to dissolve the sugar. Bring the water to a gentle boil and keep it simmering. Sugar can be replaced by Splenda or Stevia for a low-calorie option. Do not use NutraSweet. Keep the syrup mixture hot after the sugar has dissolved. Do not keep boiling it. If you continue to boil it, the syrup may burn and they you will have to start all over. Place the jars in the dishwasher. Run the dishwasher for a full cycle. Sterilizing the jars ensures that no bacteria will grow in your canned peaches. Bring a pot of water to a boil. Place the jar lids in the boiling water. Keep the lids in the boiling water until the jars are filled. Use a magnetic lid lifter to retrieve the lids when you are ready for them. Wear gloves to avoid any burns.Magnetic lid lifters can be bought on Amazon or at Target and some grocery stores. To make your own jar grabber, simply place rubbed bands at the end of a pair of tongs. Place the cut peaches into the simmering syrup mixture. Stir the pot for 5 minutes.Ladle the peaches into the jars directly from the mixture. Leave ½ to 1 full inch of space at the top of the jar. Pack the peaches tightly into the jar. Run a rubber spatula between the packed peaches and the jar. Doing this will remove any air bubbles trapped in the jar. Air bubbles could cause mold to grow inside the jar after it has been sealed. Tilt the jar slightly while running the spatula between the fruit and jar. Pour the syrup mixture into the jar. Leave ½ an inch of space from the top. The peaches should be entirely covered. Wipe off all spills and sugar from jar, especially the lid area. Place lids on jar and secure tightly. Place jars in a canner, leaving 1–2 inches (2.5–5.1 cm) of water above the jars. If you do not have a canner, you can make your own. Find a pot or saucepan that is large enough to hold the jars. There should also be room for an inch of water above the jars. Place a washcloth or towel at the bottom of the pot before you put the jars in. This will keep the jars from directly touching the metal of the pot. Calculate the canning time. Canning time varies according to the type of canner you have and the altitude of your location. Be sure to check your canner's instructions. If you are using a boiling water canner, these guidelines should help. For 0–1,000 feet (0.0–304.8 m) above sea level, cook for 10 minutes. For 1,001–3,000 feet (305.1–914.4 m), cook for 15 minutes. For 3,001–6,000 feet (914.7–1,828.8 m), cook for 20 minutes. If you are above 6,000 feet (1,828.8 m), cook for 25 minutes. If you are using a dial gauge pressure canner or a weighted gauge pressure canner, you will need about 8 minutes. Clarify with the instruction manual of your canner. 
Select your peaches. Place the peaches in a bowl. Blanch peaches in boiling hot water. Quarter the peaches. Pour ¼ cup of lemon juice onto the peaches. Fill a pot with water. Stir the mixture slowly to dissolve the sugar. Keep the syrup mixture hot after the sugar has dissolved. Place the jars in the dishwasher. Bring a pot of water to a boil. Use a magnetic lid lifter to retrieve the lids when you are ready for them. Place the cut peaches into the simmering syrup mixture. Leave ½ to 1 full inch of space at the top of the jar. Run a rubber spatula between the packed peaches and the jar. Pour the syrup mixture into the jar. Wipe off all spills and sugar from jar, especially the lid area. Place jars in a canner, leaving 1–2 inches (2.5–5.1 cm) of water above the jars. Calculate the canning time. 