I wanted to add that bit about the lemon juice and water that Glasshen mentioned to prevent browning while you are preparing the fruit also.
The USDA recommends not to use cornstarch as a thickener when canning, not sure of the "official" reasons but I would worry about it failing after time in storage. I find that when I thicken with cornstarch, if leftovers are stored in the fridge for any length of time the sauce breaks down and gets watery.
ClearJel is the only USDA approved thickener for canning, take that as you may. I have used it and it works very well, it is just very hard to find. Gives you that nice clear sauce that you see in the photo of the canned apples.
Also, I remember my mom sealing her jams and jellies with parafin wax. I also remember needing to check for mold under the wax every time we opened up a new jar. We threw away a number of jars of preserves every year because they went bad.
The USDA recommends not to use cornstarch as a thickener when canning, not sure of the "official" reasons but I would worry about it failing after time in storage. I find that when I thicken with cornstarch, if leftovers are stored in the fridge for any length of time the sauce breaks down and gets watery.
ClearJel is the only USDA approved thickener for canning, take that as you may. I have used it and it works very well, it is just very hard to find. Gives you that nice clear sauce that you see in the photo of the canned apples.
Also, I remember my mom sealing her jams and jellies with parafin wax. I also remember needing to check for mold under the wax every time we opened up a new jar. We threw away a number of jars of preserves every year because they went bad.