Garlic olive oil usually refers to an olive oil that has been flavored or infused with garlic. Commercially-produced garlic olive oil is fairly widely available for purchase, or it can be made at home. Like other flavored olive oil, garlic olive oil is commonly served as a dipping sauce for bread or crackers, or as a dressing for salads, vegetables, pastas, or meats.
Commercially produced olive oil can either be flavored with garlic by initially pressing the olives with garlic, or the oil may be infused with garlic through a hot infusion process in which the garlic is cooked in the olive oil. For the latter hot infusion process, the garlic is typically preserved with a vinegar or brine solution prior to being cooked with the oil. The preservation step prevents the water-containing garlic from developing bacterial growth. If improperly preserved, garlic infused olive oil can be contaminated with Clostridium botulinum, the microbe that causes botulism.
To make garlic olive oil at home, a simple hot infusion is usually the safest and most common approach. Garlic cloves are chopped or pressed and cooked gently on the stovetop with the olive oil. Usually, the garlic pieces are then strained out of the oil, although they can be left in the oil if it will be consumed immediately. The garlic olive oil should be used within 24 hours, or stored in the refrigerator for several days to a week. After about a week, the fresh garlic olive oil is susceptible to potentially dangerous levels of bacterial growth, and should not be consumed.
Roasted garlic olive oil is a common recipe variation, and is made by roasting the garlic cloves in the oven before cooking them with the olive oil. When the olive oil is being served, its flavor profile can be made more complex with the addition of vinegars, or a spicy element such as pepper. When served as a dipping sauce, it is common to add a dollop of balsamic vinegar to the garlic olive oil.
Garlic olive oil is most commonly associated with Mediterranean cuisine. Indeed, the consumption of both garlic and olive oil likely originated in the Mediterranean. The history of both garlic and olive oil stretches back to ancient civilizations that flourished in the Mediterranean Basin as early as 2,500 BC, and possibly much earlier. Cultural knowledge and lore regarding the health benefits of both olive oil and garlic have been passed down from those ancient civilizations, and scientific research has uncovered evidence of at least some of these benefits.