A couple of days ago, I found some picture-perfect Genoese basil at my local farmstand. I took it home, threw it into the food processor with the other requisite pesto ingredients (pine nuts, good olive oil, Parmesan, salt, pepper, garlic) and made a lovely looking and aromatic pesto. I decanted the stuff into a glass bowl, coated the top with more olive oil and put it in the refrigerator, well wrapped, where it stayed, sealed, for 24 hours.
When I sauced some pasta with this pesto the next day, it oxidized on contact, turning a dull olive brown color. Worse, it lost a great deal of its flavor.
Can any of you help diagnose the problem? Was my mistake storing the stuff? Does homemade pesto need to be used immediately? And if so, how does all-natural, commercially packaged pesto retain its color and flavor sitting in refrigeration for considerably longer than a day?
Any and all advice would be welcome!