Line a butter dish or container with baking parchment and set aside. Meanwhile, put the vinegar, salt, nutritional yeast, aquafaba and turmeric, if using, in a high-powered blender. Blitz until thoroughly combined.

With the motor running, slowly drizzle in the cooled coconut oil, then the rapeseed oil, blending continuously until the mixture is thick. Scoop the butter into the prepared container and cover with another sheet of baking parchment. Chill overnight to set. Will keep covered for two weeks in the fridge.