A question about a recipe: April Bloomfield's Lemon Caper Dressing

Yes, davidpdx is absolutely right, and you don't even really taste the sugar in the final dressing -- it's there to just mellow the tartness of the lemon.

I haven't tested storing it for longer than an hour yet -- I'm sure you could get away with it, it just might start to taste less fresh and punchy the longer it sits.

I suspect Ms. Bloomfield uses superfine sugar because it would dissolve more easily. In that case, you could just use regular granulated sugar and stir it into the lemon juice until it dissolves. I also suspect that the exact measurement is pretty inconsequential, but, analogous to measuring kosher salt vs regular salt by volume, the larger crystals of granulated sugar would suggest using an extra pinch. Finally, when it comes right down to it, you also could experiment with other sweeteners, such as honey.