Ingredient

Basil

Heat destroys it, so it goes in at the end or not at all — the exception being a sauce where it infuses whole and is then lifted out. Bruising the leaves by chopping with a blunt knife turns the cut edges black within minutes.

Sourcing
A living pot on a windowsill outlasts a cut bag several times over. Thai basil is a different plant with an aniseed note and is not a substitute for the Genovese kind.
Varieties
Genovese, Thai, Holy basil, Lemon basil, Purple basil
Quality cues
Bright green, unblemished leaves. Black spotting or translucent patches mean cold damage, which is usually the fridge's fault.
Substitutions
Flat-leaf parsley, Mint
Storage
Never the fridge — it blackens below about 10°C. Stand the stems in water on the counter like a bunch of flowers.
Shelf life
4-5 days in water at room temperature
Nutrition

Per 100 g

Calories
23 kcal
Protein
3.1 g
Fat
0.6 g
Carbs
2.6 g
Fibre
1.6 g
Sugars
0.3 g
Sodium
4 mg

From USDA FoodData Central (#172232). Raw, edible portion.