I tend to use a lot of lemon zest in my cooking, often in recipes where lemon juice is not called for. This leaves me with a lot of denuded lemons in my refrigerator.
I try not to waste them, so I squeeze the juice into a glass of water, or put a cut up lemon in the dishwasher, which I read once, somewhere, helps keep the inside of the machine clean. I haven't done any scientific analysis to check the results, but it makes a kind of sense given lemon's cleansing properties, and it makes me feel virtuous, and thrifty.
But sometimes I can't keep up with the naked lemons, and I wind up with a bit of a backlog.
So at this time of the year, I turn to the citron presse. Citron presse is a sophisticated name for what is essentially, DIY lemonade, or lemon soda. I have read this is very popular in French cafes, but having never been to France (sniff), I cannot say firsthand.
I can't really give you a recipe, but more of a method, which is really more my style anyway; I am too much of a winger in the kitchen (too organic, to use yoga-nerd speak) to follow recipes precisely.
What you do is squeeze the juice of two lemons into a glass; I use an old fashioned glass. Then add granulated sugar, or simple syrup, to taste. I don't usually measure, but I'd say it amounts to between 2 and 2-1/2 tablespoons of sweetener. Start with a smaller amount, taste, and add more if needed.
Granulated sugar is nice because it never fully dissolves, giving you the pleasing crunch of sugar crystals. But just as often, I use simple syrup, which I tend to have on hand for cocktails. You can buy this in a bottle, if cooking is not your thing, but honestly, you would be ripped off because it couldn't be simpler to make (hence, the name, I guess). Mix equal amounts of sugar and water, bring to a boil, lower the heat and allow to cook until the sugar dissolves completely, which won't take long at all. (Even if you let it cook a little longer than you anticipated, it will still be fine. It's very hard to mess up.) Let it cool, and store in a glass jar in your refrigerator. It keeps forever, which is great pay-off for so little work.
Fill the rest of the glass with water (and ice, if you like; I don't), or, my personal favorite, seltzer or fizzy water. Stir, and drink.
This works equally well with lime juice, which, I think, would make it, a citron vert presse. But my French is terrible (read: non-existent), so don't quote me on that.
Besides, I've no idea if the French make such distinctions regarding this beverage. If you've been there, let me know.