Makes a few drinks, around 6, depending on the size of your Old Fashioned glasses
Ingredients
⅔ cup freshly squeezed lime juice
⅔ cup water
1 cup sugar (you may adjust, depending on how sweet the peaches are)
3 large, ripe and juicy peaches, roughly chopped. You can decide if you want to leave on the skin. It gives a deeper blush color to the syrup than without the skin, if you do.
Whiskey, about ¾ cup (though you may want less -- see my notes below). I LOVE the 1816 Cask Whiskey from the Tennessee Stillhouse in Chattanooga, TN, if you can get it.
A few handfuls of ice
A few splashes of seltzer water -- have at least a liter on hand (or cold water if you don't want the bubbles)
Another peach, for garnish if desired (I like using the cooked peaches from the syrup)
Instructions
Roughly chop peaches. Add peaches, sugar, water to a sauce pan. Cook on medium heat to soften peaches and dissolve sugar. Mash some of the peaches with fork gently to release the juices. Off the heat. Add lime juice. Set aside to cool completely.
Strain syrup with fine sieve. It depends on how large your peaches are, but you should have about 2½ cups of syrup. Chill before using, if possible. Save peaches for drink garnish or use on top of granola or yogurt.
Put all of syrup and ¾ cup (or less) whiskey into a pitcher. Stir well. (see NOTE below on individual drink ratios)
Pour and divide stirred mixture into about 6 Old Fashioned glasses filled with ice, top with seltzer, stir well but gently, and top with peach garnish, cooked or newly sliced. Serve cold.
NOTE: To tailor each person's drink, make them separately. I do not make these drinks strongly alcoholic. I balance the sour, the peach, and the whiskey burn pretty well, though I'm sure some people might like a little more of the whiskey. Each drink should have about 2½ tablespoons peach syrup, 1 tablespoon whiskey (up to 2 tablespoons), and topped off with enough seltzer and ice to fill a mid-sized Old Fashioned glass. Wikipedia reports Old Fashioned glasses range from 6 to 10 fluid ounces. You may need to adjust your ratios depending on the size of your glass to make a more balanced drink. The ones I use in the photographs are a 10 ouncers, and I've used 8 ouncers. In general, you want your syrup to whiskey ratio to be 2.5 : 1 or 2.5 : 2 then add enough seltzer/water and ice to make it tasty.
Recipe by story of a kitchen at https://www.storyofakitchen.com/drink-recipes/peach-whiskey-sours-recipe/