Hi all I’m in need all your brilliant minds... I’m baking my sisters wedding cake in a few months and she wants a white rustic finish which could be made using a palette knife using either royal icing or buttercream... my problem is can I cover the sponge cake completely with royal icing ?? My sister doesn’t like the taste of sugarpaste. The alternative would be to use buttercream but it never goes completely white and always has a yellow tinge to it. Can anyone please help with either explaining the process to use royal icing or how to make buttercream white 

I’ve added a pic below of the kind of look we are going for.

thanks everyone in advance 

It sounds like you are using a b’cream recipe of 1/2 butter & 1/2 shortening   It will never be pure white but will come very close the more you mix it   That’s why the recipe “2 of everything “ is such a good choice   I don’t know about using Royal for covering the cake   Here in the US it is never used for that   Since your cake will be a semi naked finish I don’t see where the b’cream color is so important—but that’s just me  — it will look white to almost everyone 

I love this type of buttercream finish.  Personally, I don't think the creamy tone will make any difference, but I've heard others advise adding a tiny touch of purple color to neutralize the yellow tint.  I use Wilton white food color, which does a pretty good job.  You can use all shorting, if it must be pure white, but for the different in taste and texture, I would elect to go with the creamy tone every time.

also the lighting at the venue will disguise, determine and diffuse the cake color -- it's a daunting task to try and get a perfect white -- seriously it won't matter a whit after you deliver that cake -- wasted effort -- freal -- for one thing you have to decide which white is the right one in the first place -- but that aside if you let your icing mix for an extended period of time -- it gets lighter and whiter 

not to mention -- royal icing a sponge cake is not advised at all -- just say no to that one

Sandra I'm forgetting sooo many of those 'old time' hints.  Yes, using just a teeny bit of voilet will help whiten some but there is a very thin line between how much is enough and how much is over the line :)    And as K8 said there are something l;ike 50 shades of white!  Ask a painter:) 

i just flat out told my brides that their icing would be a tad off white due to butter and real vanilla -- they could lump it 

-K8memphis, your attitude is exactly like mine, if they don't like it, they can lump it, haha!

Add another one to that list   I had only one bride complain when I delivered the cake   She had rented linens that were soooo blue white it was ridiculous   That of course made the cake look more beige than anything  & it was an outdoor  summer wedding—-dazzleing sunshine

sandra