Why do we bruise herbs?
We bruise herbs to release their aromatic oils. To bruise herbs, gently roll and rub a bunch of sprigs in your hand or tap loose leaves with a mallet or the back of a knife.
A recipe may call for bruising herbs in lieu of chopping them when the herbs are not intended to be eaten. We add sprigs of bruised thyme to simmering vegetable soup and then remove the sprigs before serving. Make flavored oil by stuffing bruised rosemary or basil into a bottle of olive oil and letting it stand for at least a day.