Welcome to the Cake Decorators Q&A
Hi fozzie57
Dairy and nut free free chocolate, cream or milk are all readily available in all major supermarkets. It depends on the severity of your grandson’s allery and tolerence. There are several suppliers online who may be able to advise you better. Here is one supplier whom you could speak with : https://www.freefromforkids.co.uk/
Sharp edges using ganache can still be achieved regardless of the ingredients. All you’ll need to do is adjust quantities of liquid to chocolate ratios. Hope this helps. Please do post again if you would like more information.
Edit: My apologies, you did say no ganache. Sharpe edges can still be achieved using buttercream, even that which is made with non dairy butter.
The cake has to be well chilled in the fridge before crumbcoating and after each subsequent masking. On first chilling, wrap the cake well in cling film to prevent the cake drying out in the fridge. Crumbcoating will seal the cake so it won’t be as necessary to use cling during further chilling.
It also helps to use more icing sugar to fat ratio to make a stiffer buttercream with the non dairy spread.
Chilling the cake will prevent the icing tearing the cake layers as you begin to crumbcoat. You could also add melted chocolate to the buttercream to make it more stable. Dairy free chocolate is available online and in supermarkets. Once you cover the cake with sugarpaste, the structure will stablize as the paste begins to dry. Store the decorated cake in a cardboard box in the coolest place you can find in your home.
Please let me know if this helps or if you would like more information.
Good luck with the cake Pauline! Looking forwards to hearing how you got on.
