This is an icing for biscuits that sets hard with a glossy sheen that gives it a classy polished look! Demonstrated here with Christmas Cookies and also seen in Gingerbread Men, but this is an icing recipe you can use for any cookies, any colour, any occasion!
Bonus: I’m also sharing my fast biscuit icing method to cover the entire surface of a cookie quickly and easily, without piping!

Icing for biscuits
This is the icing recipe for the Christmas Cookies I just shared. The recipe got too lengthy so I decided to split it into two – and also, this is an all purpose icing recipe that is ideal to use for any cookies and biscuits, not just for the Christmas Cookies!
This is an icing for biscuits that:
sets hard;
doesn’t soften your cookie ie won’t affect the shelf life of the biscuits;
has a light, glossy sheen that gives it an extra special look;
has the perfect consistency to spread smoothly to cover the surface AND to pipe details;
can be used to DIP biscuits in to cover surfaces quickly (my cheeky quick method -see below!); and
can be made any colour you want.

Here’s what you need

Corn syrup is what gives this icing a lovely sheen. Corn syrup isn’t widely available in Australia (yet) BUT you can substitute with glucose syrup. This recipe works perfectly well without corn syrup too, but the finish will be matte instead;
Egg whites – the secret ingredient that makes the icing set hard! KEY TIP is to MEASURE the egg whites rather than relying on just using “2 egg whites”. This is because the size of eggs differs every time but the amount of egg white used in the icing will materially affect the thickness of the icing – and the key to icing is getting the thickness perfect!
See below info box for concerns about raw egg.
Icing sugar / powdered sugar – fellow Aussies, be sure to use SOFT icing sugar, not pure icing sugar.
Colouring – gel is better if you can get your hands on it because it has a more intense colour so you need less, but recipe works perfectly fine with liquid too (in fact, I use liquid in the video).
Addressing the raw egg concern!
One of the most asked questions about royal icing is the concern about the use of raw egg whites in royal icing.
Well actually, the egg whites do not remain raw! The sugar in the icing essentially “cooks” the egg. The more appropriate terms is “curing” because the effect of the sugar on the egg is the same as using salt + sugar to cure things like salmon to make cured salmon (like this Beetroot Cured Salmon and Gravlax).
How to make icing for biscuits

The making part is a cinch (the icing part is the painful part!!):
beat the icing sugar, egg whites and water until smooth and glossy;
divide between bowls, then mix in colouring. Go by eye until you achieve the colour you want – different brands, gels vs liquid all require different amounts;
make sure the icing is the right thickness – use the “figure 8” test ie draw the number “8” across the surface, it should hold for 2 seconds before it disappears. The icing needs to be thick enough so decorations you pipe hold their shape, but thin enough so you can spread the icing across the surface of the biscuit;
transfer into piping bags OR ziplock bags. See below re: piping nozzle (I don’t use one!)
Icing with piping bag
Here’s how to ice with a piping bag.

I do not use a nozzle because I don’t have a nozzle fine enough to give me the detail I want when icing Christmas Cookies. You literally want the nozzle to be 1 – 2 mm wide – well, “thin”, I should say! When the hole is that small, you have enough control to pipe it without a piping nozzle so just snipping the end of a piping bag or ziplock bag works a treat.
ONE NOZZLE TIP: If you DO have a thin nozzle, but you only have one, then use the double bagging method to use the same nozzle for multiple icing colours:
place nozzle into a clean piping bag “Nozzle Piping Bag”;
place the different coloured icing into separate piping bags WITHOUT a nozzle, snip end;
place one colour into the Piping Nozzle Bag and pipe away (ie using a double bag);
once done with that colour, remove the icing from the Piping Nozzle Bag; and
remove and clean nozzle, then put it back in the Piping Nozzle Bag. Insert next colour and repeat.
Shortcut icing method
Here’s a quick way to frost the biscuits without fussing with piping bags!

Place skewer on edge of bowl;
Dip surface of biscuit into frosting;
Scrape off excess frosting along the skewer; and
Voila! Frosting, done! Add some sprinkle, some silver balls while it’s wet so they stick.

How to store leftover royal icing
Keep leftovers sealed in a piping bag in fridge for one week or freezer for 3 months. I fold the snipped end of the piping bag and secure with sticky tape.
Note on royal icing batch size
This recipe for royal icing makes more than you need for one batch of the Sugar Cookies/Vanilla biscuits pictured in post. But you want to err on the side of caution if using multiple colours because you will lose some through handling, especially if using multiple colours.
Use for any biscuit or cookie!
The photos depicted in today’s recipe are a vanilla biscuit that I shared for Christmas – see below (aka Sugar Cookies!). That particular recipe is made for cut out cookies because it holds its shape when baked, rather than spreading or puffing up, and cut out cookies are usually the ones that are decorated with icing.
But the frosting can be used for any cookies at all, including gingerbread men and gingerbread house!
I hope you enjoy – and have fun with this icing! Think of the possibilities! – Nagi x
Watch how to make it
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Icing for Biscuits (Royal Icing)
Ingredients
Icing:
- 500g / 1 lb icing sugar / powdered sugar , sifted (plus extra for adjusting) (Note 1)
- 1/4 cup egg white (2 small eggs or 1.5 large eggs) (Note 2)
- 2 tbsp corn syrup (or 1.5 tbsp glucose syrup, Note 3)
- 1.5 tbsp water , plus more as needed
Colouring:
- Food Dye – liquid or gel , go by eye for quantity (Note 4)
Instructions
- Place Icing ingredients in a large bowl and beat for 1 minute on speed 5 until smooth and glossy (start on low then speed up).
- Divide icing into different bowls for colouring. Add food dye and mix – keep adding colouring until you achieve the colour you are after. If icing gets too thin, add more icing sugar.
- Icing consistency test: Should be able to draw a figure 8 on the surface and you can see if for 2 seconds before sinking in and disappearing. Should be thick enough to pipe details but thin enough to spread smoothly on surface of cookie. ADJUST icing – thinner with water (1/2 tsp at a time), thicker with more icing sugar.
PIPING:
- Transfer icing into disposable piping bags or ziplock bags.
- Snip the TINIEST bit off the corner. Smaller hole = better detail in icing. Remember: You can cut hole bigger, but not smaller! OR using very thin piping nozzle.
- Pipe decorations on cookies as desired.
- Decorate with sprinkles etc while wet (so they stick). Or dry completely before piping on details.
- To fill a large surface, use toothpick to spread.
QUICK METHOD to ice biscuits (see video demo):
- Place skewer on edge of frosting bowl.
- Hold edge of cookie with two fingers, then carefully dip face of cookie into frosting.
- Pull out of frosting then lightly scrape surface across skewer to remove excess.
- Decorate with sprinkles etc while wet (so they stick). Or dry completely before piping on details.
Recipe Notes:
Tip: Red icing requires a LOT of colouring, about 3/4 tsp (for 1/3 of the icing mixture). 5. Yield – makes more than enough for one batch of these Sugar Cookies/Vanilla biscuits. But you want to err on the side of caution if using multiple colours because you will lose some through handling.
Nutrition Information:
Life of Dozer
This is called a Sugar Coma.

Hi Nagi,
Can I microwave this icing? Thank you
Hi Andre – you don’t cook this one. N x
Hi there. How can I adjust the ingredients for just 10 cookies?I’m using your Christmas Sugar Cookies recipe
There’s a sliding scale at the top of my recipes that. you can use to scale up or down! N x
Aww yes silly me. Thank you for your reply!
Hi Nagi, how long can I store the iced cookies in the cupboard ? Just regarding the egg white ?
Thanks so much , Sam
Hi Sam – if you have used pasteurised eggs (check the box) then the risk of food illness is pretty low on these and the sugar is a preservative too. But if you are at all concerned then store them in the fridge. N x
Hello can’t wait to make these but was wondering if golden corn syrup will work?
Hi Valerie – it should although it might affect the white colour of the icing. N x
Do you know how long these can be stored at room temperature?
I’m planning to make them and send in the mail. Thank you.
They will be fine for a couple of days! N x
Hi Nagi, thank you so much for all your wonderful recipes! I’ve learned so much about baking from you.
Can this icing be made ahead of time and stored in fridge for a couple days?
We are going to a cabin for the weekend and I’d like to decorate cookies with the kids, but won’t have access to a mixer etc…thanks in advance
It should be ok in the fridge for up to 3 days. After that it changes texture. Make sure its in a piping bag or very airtight container! N x
Hi is it ok if i substitute corn syrup with honey?
Adding flavoring to icing. How much for this 1# recipe?
Wow super
Hi Navi,
I bought some rubber stampies (https://www.wemightbetiny.com.au/products/stampies), would this icing work?
I’d probably have the icing dry a little first before stamping it.
Also, Dozer is a cutie (speaking from a fellow GR mum 😉 )
*Nagi
(Stupid iPad autocorrect)
Hi Nagi, I have try these various icing methods on Christmas. Thanks for these wonderful icing biscuits.
Hi I tried your icing recipe. May I know how long it takes to set hard in open air? I read that it usually takes 6-24 hours. Will this setting cause to vanilla cookie to soften after been exposed to air? Thank you
Adding flavoring to icing. How much for this 1# recipe?
There are some pasteurized liquid egg products here in the US such as Egg Beaters with just egg whites. I’m going to try substituting in a small batch to avoid using raw eggs. Hopefully I can find the one without yellow food coloring.
Hi Gloria, yes that will work fine! N x
Hi Nagi, I know you said icing mixture rather than pure icing, but I have only pure icing. Kids wanted to ice it tmr 7am 🙄Would adding a bit of corn flour into the pure icing (from googling) work by any chance? Thanks
How do I make icing harden?
Hi Shane, it will harden as it dries naturally! N x
Hi Nagi,
How long can I keep my icing?
Becuase of the eggs white, can I leave it outside the fridge at room temperature?
Thanks a lot! I love your cookies…..
Hi Martha, yes you can store the cookies that are iced at room temp, do not store in the fridge 🙂 N x
Hi Nagi!
Thanks for the great royal icing recipe! Do you think this icing will be strong enough to hold together a gingerbread house? I’m thinking of making one this year for christmas!
Thanks!
Hi Matt, no sorry, you need a thicker royal icing for gingerbread houses, it’s thicker and stronger, it acts more like a glue 🙂 N X
Hey how much where are the measurements?
Hi Nagi, I know you said icing mixture rather than pure icing, but I have only pure icing. Kids wanted to ice it tmr 7am 🙄Would adding a bit of corn flour into the pure icing (from googling) work by any chance? Thanks
Hi Nagi. Wondering, can kids eat the icing? Coz we are not cooking the egg at all.
I’ve used a similar icing recipe with egg white for Christmas cookies for many years – no problem for any of the kids who have had them. Would only be an issue if they had egg allergies I think.
Are the leftovers freezable? – I can never get the ratio of icing made to cookies made, and don’t want any to go to waste (I don’t have easy access to quality icing sugar for the rare cookie-decor occasions)
On cooking shows, you hear so often about egg whites needing to be cooked when you make royal icing, or that meringue powder is a better option. Could someone please elaborate.