It's very simple, but requires endurance. Lemon cut into slices. Place them in a jar (bottle), add sugar and vinegar (I used wine).

Add the water, filtered or boiled, but not mineral (minerals may not give occur the phenomenon of fermentation). Jar to cover, leaving a small hole, and put it in a warm Sunny place (I put it on the window sill with the included battery) for 7-8 days. Every day, I would not drink, do not be afraid of smells of a light fermentation. After 7-8 days, the beverage drain and refrigerate in a tightly sealed bottle (fill no more than 2/3) even for 2-3 days.

Needs to be replaced, at home we are cool, and the fridge is too cold (stops the fermentation process and destroys the bubbles), so the lemonade stored at room temperature before use and cooled with ice. Shelf life - 2 months. Attention! Caution when opening the bottle, a powerful gas! :))) And yet, my husband said he had a little taste and added sugar and a slice of lemon, and I was so good, so what, if anything, it is possible to correct. ;)