Add eggs, one cup sugar, salt, and milk to a large saucepan over low heat. Whisk until thoroughly blended.
Continue whisking or stirring every minute or so until the mixture thickens and reaches 160 degrees as measured with a candy thermometer. (This step takes 40-50 minutes. Important, do not turn up the heat or try to hurry this step and do not allow the mixture to come to a boil or you will end up with scrambled eggs.)
Place a large bowl in the refrigerator to chill.
Remove the custard mixture from the heat and immediately transfer to the chilled bowl placed in a pan of ice and water to cool it down. Stir in the sweetened condensed milk and vanilla and mix well.
Take a piece of plastic wrap and press it down on the surface of the custard and refrigerate for several hours or overnight.
Place the chopped peaches and peach preserves in a bowl and add the remaining 1/4 cup sugar. Mix well and let the peaches macerate for at least 30 minutes. Use a potato masher or fork and mash the peaches. I usually like to leave mine fairly chunky.
When ready to make the ice cream, fill an electric ice cream maker 2/3 full with the custard mixture and add some of the peaches. Depending on the size of your ice cream maker you may have to make two batches. My ice cream maker only holds 2 quarts, so I divided the custard mixture and added half of the custard and half of the peach mixture.
Follow the directions for your ice cream maker and freeze the ice cream. This step took 20 minutes with my ice cream maker. It may be different with yours. Refrigerate any remaining custard and peach mixture to make a second batch.
Place the ice cream in an airtight container in the freezer and freeze for 2-4 hours or until firm. Repeat with the second batch, if necessary.
Frequently asked questions:What kind of peaches work best in this recipe?Look for soft, slightly overripe classic yellow peaches. Like overripe bananas in banana bread, soft overripe juicy peaches work best in this recipe.How to tell if a peach is ripe?If you will be using them right away, look for softer peaches with a strong peach smell. If you plan to use them later, choose firmer peaches with a fainter peach smell.How do I store peaches?Don’t wash the peaches until you are ready to use them. Keep them at room temperature, stem-side down on your kitchen counter.How to peel peaches without a knife?To easily peel peaches, place them in a large pot of boiling water for 10-15 seconds. Remove them from the boiling water and immediately plunge them in ice water. Rub the peel with your fingers and it will come right off.[nutrition-label]