Pesto

Yes, up to 1 day in the fridge. Transfer to an airtight container and press a piece of plastic wrap directly onto the surface to prevent browning. Store for up to 24 hours. You can also freeze pesto in ice-cube trays for up to 3 months; thaw at room temperature before serving.

Oxidation and heat turn basil dark. Avoid using a blender, which heats the herbs; use a food processor and pulse, not run. Rinse and completely dry the basil before processing, and use the pesto within hours of making it. Lemon juice slows browning—don't skip it.

Walnuts are the traditional substitute and cost less; use 1/3 cup toasted walnuts for the same amount of pine nuts. Almonds or cashews work too, but they taste slightly different. Toast whichever nut you use, as it brings out oils and flavor.

Traditionally, toss it with hot pasta (2–3 tablespoons pesto per serving) and finish with fresh Parmigiano-Reggiano. It also tops soups, spreads onto bread, garnishes grilled fish or chicken, or swirls into cream for a quick sauce.

No. Pesto requires fresh basil for its bright, herbaceous flavor. Frozen basil turns mushy and dark when thawed; dried basil tastes nothing like fresh. Make pesto only when fresh basil is available in summer, or freeze homemade pesto instead.

Press plastic wrap directly onto the surface to prevent browning, then refrigerate for up to 1 day. Or freeze in ice-cube trays: pop cubes into a freezer bag and freeze for up to 3 months. Thaw cubes at room temperature and use within 30 minutes of thawing.