They say you mustn't play with your food. Especially not when it comes to a true Italian delicacy such as pesto. This famous sauce made from ground basil leaves, garlic, salt, Pecorino or Parmesan cheese and pine nuts with olive oil is not to be messed with. Except if you can help it taste nice for longer.

We've all been there. You really fancy a tasty pasta with pesto but the jar of pesto is past its sell-by date. What a pity! It never has to be a problem again. You can extend the shelf life yourself.

If you keep the pesto under a layer of oil at all times, it doesn't decay basically. And so you can lengthen the shelf life by a week or so. Make sure you keep the pesto in the fridge, because it will certainly not last in a cupboard, once opened...