Juice (?) day: Springfield Lemon Co. Lemonade

Not sure what to call this, as it's not a brew day, but here's the scoop... I have one tap on my keg that's dedicated to non-alcoholic beverages. In the past, we've alternated between our Swearengen's Old Tyme Root Beer and our Ten Percenter Seltzer. Well, last spring we visited some friends in Seattle and while enjoying a game at Safeco Field I noticed that they dispensed their "fresh-squeezed" lemonade from kegs and just threw half a lemon in the cup before pouring. That gave me an idea which today became Springfield Lemon Company 100% Natural Lemonade.

The idea is pretty simple: lemon juice, sugar and water go into the keg. When you want a glass of lemonade, you throw a handful of ice into a pint glass, squeeze half a lemon into the glass, throw the lemon rinds in, and fill 'er up with lemonade from the keg. The tricky part was coming up with the proportions. I made several test batches and determined that a pint glass with 2.5 oz. simple syrup, 1 oz. lemon juice, one half lemon, about a third of a glass of ice, and water made some damn good lemonade. But issues of scale complicated things; namely, estimating how much the ice and lemon skewed the volume of the glass so I could figure out what should go into the keg. I ended up calculating the following for a 2-gallon test keg:

2.5 cups lemon juice (~6 oz. made from fresh lemons in my juicer; the rest store-bought)
6.25 cups simple syrup (4 1/8 c. sugar heated in 4 1/8 c. water)
1.5 gallons water

The first glass wasn't bad, but it was a little sweeter than my test batch. Maybe I screwed up on my proportions, or maybe it's just an issue with the simple syrup not being fully mixed yet (I've noticed my first couple pints of root beer always seem to be stronger). The other issue is it still has a slight root beer taste. I've also noticed that with the first pint or two of seltzer; we'll see if it goes away or if I'll need to get a new keg for non-root beer products.

Oh yeah, one other issue... I don't have separate regulators for the separate kegs in my kegerator. As such, this keg would normally be under 12 psi, which will yield carbonated lemonade in a matter of days. What I've done is turned off the valve to the keg and purged most of the CO2 so it pours slowly and hopefully isn't under too much pressure. When it starts pouring too slow, I'll just give it a kick of gas. We'll see if that proves too tedious, or if we end up with carbonated lemonade soon. I'll be sure to post how things turn out.