Help! Royal icing pouring off cake

[FatSatsumaStuffedIntoAStocking]

Homemade royal icing, following Tamasin Day Lewis's recipe. Made it correctly, let it stand for an hour before icing cake. But it's so runny it's not sticking to the marzipan properly. It looks ok on top (v glossy, no snowy effect) but a bit bald on the sides. Will it harden up??

It's got a bit too much water in - it only needs to be a few mls and it all goes tits up, as mine did last year. You probably haven't got time to do another coat but it will still taste lovely. Ribbon round the sides?

Wow, that doesn't sound right! I don't know the recipe you are using, but it shouldn't be runny - royal icing is basically a meringue, ie egg white with a lot of icing sugar in it to make it stiff. No water needed . Can you start again? Or if you have some left over, beat in some more icing sugar so it will stick to the sides (you'll need to apply it with a palette knife).

No water in it, just egg whites, sugar and 2 tsps lemon juice.

Have scraped up the pool round the outside and beaten it more, like a stiff meringue. Now trying the sides again - thanks for your ideas

If beating it again doesn't work put the remainder in a container in the fridge and let what is already on the cake dry overnight (put it in a warm room to help it along) then put the remainder on (it should be thicker after being in the fridge). Keep it in a warm room to dry out. And next year either use Delia's recipe and ice it a week before to give you more time, or buy some fondant like I will next year

You need to beat it for ages, I would guess you haven't done it for long enough, it should stand up in peaks in the bowl when it's ready

You're right. But in my defence the recipe does not make that clear - she just says beat with a wooden spoon til dazzlingly white

Oohhh proper royal icing. I use the stuff in a packet.