Here's what I do to make skeeter pee. The OG should be about 1.070, it finishes at 0.098. My apologies for the non-metric measurements. Also, the only way this can be carbonated is to keg and force carbonate.
1) On the stovetop, add 8 pounds of sugar to 8 cups of water and 1/3 cup lemon juice concentrate. Heat to just below boiling and hold it there for 30 minutes, making invert sugar syrup. Turn off heat, and then
2) Add to a 6 gallon bucket or carboy two 32 oz bottles of 100% lemon juice concentrate, three gallons of cold water, 1 tsp yeast energizer, 3 tsp yeast nutrient (DAP), 3/4 tsp tannin and the invert sugar syrup you made in step 1. Top off the fermenter to 5 1/2 gallons with more water, then
3) Whip the **** out of it, mixing it completely. Gravity should be in the neighborhood of 1.070. You can add more sugar to get it there if you want.
4) Cover the opening of the fermenter with a towel, and let set 24-48 hours to (supposedly) let the preservatives dissipate.
5) Take off the towel, whip it up vigorously again then sprinkle two packets on Montrachet wine yeast over the top of the must and seal with an airlock.
6) Check the gravity, and when it reaches 1.050, add another 1 tsp yeast energizer, 3 tsp yeast nutrient, and one 32oz bottle of 100% lemon juice concentrate. Whip it up again.
7) When it is done fermenting (0.995 or so) and drops clear, rack it to a bottling bucket or keg and add 1/2 tsp potassium metabisulfite and 2 1/2 tsp potassium sorbate mixed into a 1/2 cup of water.
8) Add 6 cups sugar (more or less, to taste) and then bottle or keg.
I have this fermenting away right now, should be ready mid-spring. I'm experimenting a bit with this batch -I skipped the bottled lemon juice and am using squeezed lemon juice left from a batch of limoncello I'm making (I only needed the zest for that).