Welcome to the Cake Decorators Q&A

I am a complete novice to cake making but can anyone tell me what buttermilk is?

Hello Sharon

This http://en.wikipedia.org/wiki/Buttermilk is a good explanation, better than I can explain it. You can make your own buttermilk at home by adding a table spoon of lemon juice to one cup measure of milk. Leave it for 15 minutes at room temperature, once it has curdled you have buttermilk. Use it in any recipe which asks for it.
Hope this helps.

great thanks very much 🙂