What is in Bailey's Irish Creme?

Bailey's Irish Cream is made from Dairy products, milk with Cream that has had brandy added. The alcohol preserves the dairy component, preventing it from going sour and turning into cheese. There are many alcoholic drinks made in this way, Advocat is a famous one which also uses Egg yolks, giving it the distinctive yellow colour. It is quite possible to make your own 'Baily's', care should be taken to add sufficient spirit to preserve the dairy component.