I've made homemade pestos for years, but have always done so on the fly, never from a recipe. A few handfuls of fresh basil here, some gratings of parmesan there, sometimes one garlic clove, sometimes two, and a liberal sprinkling of pine nuts. All of this blended with the best olive oil I had always delivered a good pesto, sometimes a great one, but one that was always a little different.
Sadly, one thing that never varied with these pestos was their tendency to lose their vibrant green color and turn an ugly army green-brown just hours after being made. To make matters worse, it wasn't just the color that oxidized, it was the flavor as well, and nothing I did, like coating the pesto with a thin layer of oil, or storing it with plastic wrap pressed tight to its surface seemed to halt its degradation.
