water to cover
1 cup sugar for every 4 cups liquid
About halfway through juicing the lemons I started wondering why I was farting around with all of these steps. When I made the citrus concentrate, I put the peels back in the reserve water, to try to loosen up more juice. Then I used all of the reserved water. I quit juicing the lemons, cut them all in half, gave each a quick squeeze, then tossed it all back into the reserved water.
It's a little too much zest, but drinkable. Next time, I'll try the same method, but peel and discard the zest from about half the lemons.