Cut peaches in half and remove pits. Cut each half into medium-size chunks. Puree peaches in blender with a cup of sparkling water. It may take two to three batches depending on the size of the blender.
Pass the peach puree through the sieve using a rubber spatula into a large pitcher or container to remove any skins or large pieces. Add the pinch of sea salt and set aside.
Prep carrots, apples, lemons and ginger for juicing. (Depending on your juicer you may not have to core and peel the apples, ginger and carrots; refer to your instruction manual if in doubt). Cut apples into wedges that will fit into the juicer. The lemon is best when the rind is removed and lemon is cut into wedges. The ginger should be cut into a few smaller pieces.
When juicing, alternate the apples and carrots with the lemon and the ginger to keep the juicer from clogging up and overheating. Once the juice is collected, pass it through the sieve into the peach puree and stir.
Add 1 cup of sugar and stir again. Then add the rest of the sparkling mineral water. Taste the fresca and add more sugar if necessary. Add ice and garnish with lemon slices. Enjoy.
Note: At Phoenix Public Market all our frescas are based on organic fruits and vegetables. The ripeness and natural sugar content of the fruit will determine how much sugar you will add. The carrots add to the flavor and color of the fresca. Using green-skinned apples may "muddy" the appearance of the drink. If you decide to use them, green apples should be peeled before juicing to keep the color of the agua fresca from becoming cloudy.