Wash and gently dry basil leaves. Set aside to let air dry.
In food processor, chop pine nuts, garlic, Parmesan cheese, and salt until crumbly.
Add basil leaves, lemon juice and a little bit of the olive oil. Process briefly and scrape down bowl of processor.
With processor running pour remaining oil into basil mix to create a paste.
Taste and adjust seasoning as desired, more salt, garlic or cheese?
Fill ice cube tray or containers and freeze. Covering with oil to prevent darkening is optional.
Once frozen, transfer cubes into a freezer bag and seal well.
It will be safe to eat as long as it remains frozen. For best flavour, use within 6 months.
Keep fresh pesto in the fridge for 4-5 days only. Unlike store bought pesto, fresh, homemade pesto does not have any preservatives and it is not acidic enough to prevent harmful pathogens from potentially forming.
Notes
Store in fridge for 4-5 days only. Homemade pesto will not keep as long as commercial pesto which is processed differently and has preservatives. Pine nuts are expensive and can be hard to find - try walnuts, sunflower seeds, pepita or even hazelnuts instead. The nutrition facts show this pesto using pine nuts.The basil will oxidize and turn dark very quickly. It's harmless, but takes away from the beautiful bright green we hope for. To prevent this, either cover the pesto completely with oil right away or blanch the basil before processing. A quick 10 second dip in boiling water followed by an ice cold water bath will lock in the colour. (See article for details)Makes 1 cup, enough to make 8 (1 ounce/2Tbsp) ice cube compartments