These incredible products are achieved by a long an intricate process. Fresh herbs and/or spices are added to the olive oil and steeped for four to six weeks in the oil. At regular intervals, the oil is tested to ensure that no bacteria growth or contamination has occurred. We have these done for us and we use pure olive oil (refined olive oil with around 10% of extra virgin olive oil added to it) so the flavor doesn't compete with the infusion. The resultant product is a truly fresh herb/spice flavor that will not dissipate with cooking.