Split the beans open by cutting down the middle of the bean, then cut into small pieces and add to grape-seed oil. Close lid tightly.
Give it a good shake or stir and infuse the vanilla beans for several weeks, a minimum of two. The longer you immerse the vanilla beans, the more intense the flavor will be.
Store the jar in a cool dark place.
Notes
The beans should be completely submerged and not exposed to air.Taste the oil after a week or so and if you are happy with the flavour you can start using it.No need to strain, the beans will stay at the bottom of the jar.A preservative is not necessary unless there's added moisture or if the mixture is not properly sealed.