Chopping and Using Fresh Basil

When it comes to chopping basil, it pays to wait until the last minute.

Freshly chopped basil can quickly turn dull black through a process called oxidation. We knew that the change in color wouldn’t lessen its flavor, since we often recommend bruising the herb before using it—by releasing the essential oils, bruising actually intensifies basil’s flavor. But could we preserve color without sacrificing flavor?

Some recipes suggest dropping basil into boiling water, then transferring it to ice water to stop the cooking and “fix” the color. Two other “tricks” we’ve heard about are coating the basil in oil just before chopping it, or immediately after; in theory, these methods keep the cut basil from being exposed to air and therefore from blackening.

To see if any of these options had merit, we made tomato salads with equal amounts of basil that were prepared in these three ways, as well as one with basil that we chopped and added just before serving. Although the leaves fixed in boiling water stayed bright green, it was an awful lot of trouble to go through for a garnish or breezy summer dish. Coating the unchopped basil in oil made it slippery and difficult to chop and barely slowed the blackening. Coating the chopped basil in oil did slow the color change, but it also made the basil a little oily—OK in a tomato salad, but not for all preparations.

THE BOTTOM LINE   For the best flavor and easiest prep, chop basil and add it to dishes just before serving.