Can you have straight up garlic oil?

Question

Can you have straight up garlic oil or is it always garlic boiled in another oil so garlic oil always has another oil As it’s ingredient?

Is there a reason why it always seems to be olive oil rather than others?

Answer 1

Garlic oil; that is, oil directly from garlic is certainly a thing. It is usually achieved using steam distillation. I have read that the undiluted oil has about 900 times the strength of fresh garlic. That's generally much more potent than any home cook or chef wants to deal with. For the vast majority of culinary applications, garlic is used to flavor oil. Any oil will work, and the way the garlic is chopped (or not), as well as how it is heated (and how long) in the oil, will have significant impacts on the final result.

Answer 2

Culinary oils are made by pressing an oil-rich food, and mechanically separating the fats from the hard cell matter.

Garlic - or at least garlic bulbs - have basically no fat. There is basically nothing you can press out of garlic to end up with oil. So no, you can't produce a "garlic oil" in the sense of "oil pressed from garlic" that would be usable in the kitchen. The term "garlic oil" exists, but it means that an oil made from another plant has been flavored with garlic aromatics, either by direct infusion or by other methods.

When working with plants, the word "oil" is also applied to a different substance, called an "essential oil". Essential oils are very different from culinary oils in both their chemistry and their application, and primarily used in perfume creation or pharmacologically, not for food purposes. Some of them can be used in the kitchen, but only in the tiniest possible amount as an aroma substance, never as a cooking fat.

You can create an essential oil out of garlic, it works with any plant. I'm not deep enough into the details to know whether the distillation method will work, or if one would need other methods such as absolue or CO2 extraction, but it will be possible. The result, however, won't likely be what you imagine. Especially, it won't be edible, except maybe for microgram amounts added to food as an aroma - but even that's not certain. Essential oils even from "mild" plants can be powerful irritants, and a plant that contains harsh chemicals such as garlic will likely have an essential oil that's too toxic even at higher dilutions.