Basil pesto

No kitchen garden can have too much basil!

Basil is a fragrant sweet-smelling herb that comes in all shapes and forms from both Africa and Asia; of these, the most common and productive basil is the large sweet basil, sometimes called ‘Italian basil’ because it appears commonly in Italian dishes. ‘Lettuce-leaf basil’ is similarly productive, having a lighter-green crinkly leaf. Other basils include ruby basil, cinnamon basil, lemon basil, Thai basil and the perennial bush ‘Greek basil’. The latter forms, though colourful and equally well-loved by the bees, have smaller leaves, and are fiddly to turn into that wondrously nutritional and tasty spread – ‘basil pesto’.

Basil (except for the perennial Greek basil) is generally grown from seed in the Adelaide Hills and Plains during the warmer months of the year, and so by autumn is starting to go to seed, with long delicate flower stalks arising from the centre of each clump of basil leaves. You can still use flowering basil for pesto, but it is best harvested while the leaves are young and fresh. (We pinch off the flower tips to prolong the production of leaves). Use only the leaves in making pesto, and separate these from the stalks, which go to the compost heap.

Pesto is made from a paste of basil leaves; it’s surprising how many leaves (practically a half-a-bucket full) it takes to make a small amount of pesto. Pesto can be used as a spread on toast, as a sauce in pasta, or as a relish on roast meats such as lamb.

Pesto oxidises in air almost immediately it is made, turning from a pleasant shade of green to a muddy unattractive brown. Pesto can, however, be stored in the fridge by placing it in small glass jars and covering it with a 1 cm layer of olive oil to keep the air out. Just pour the oil into a small side dish to get at the pesto.

A bar mix is needed to grind the pesto in a small plastic jug, along with olive oil, salt, pepper, pine nuts, walnuts or almonds, cloves of peeled garlic, and parmesan cheese if you are going to eat the pesto immediately (as the cheese-version doesn’t store well). You can add parsley if you wish. In winter, we have found that we can also make a pesto from rocket leaves if the basil has run out.