What Is Fondant Icing? Types, Uses and Carbs
What is fondant icing? Fondant icing is a sweet sugar paste used to cover and decorate cakes. The kind most UK bakers buy is rolled fondant, sold as ready-to-roll icing: a soft, pliable dough of sugar, glucose syrup and a little fat that's rolled out and smoothed over a cake. Poured fondant is a thick, glossy icing made by boiling sugar syrup, used on fondant fancies and in sweets. Either way, it's mostly sugar.
At a glance
- Made fromsugar, glucose syrup or gelatine, glycerine and fat
- Main typesrolled (ready-to-roll) and poured fondant
- Namefrom the French for "melting"
- Carbs90.1g per 100g for homemade fondant (CoFID)
On this page
It's the smooth, white blanket on a Christmas or wedding cake, the pastel coating on a fondant fancy and the soft centre of a peppermint cream. If you've ever wondered what is fondant icing exactly, how it differs from royal icing or buttercream, and why some people peel it off, this guide explains it. You'll find what fondant is, the main types, what's in it, how it's used, how it compares with other icings and how many carbs it has.
What is fondant icing?
Wikipedia describes fondant icing, often just called fondant, as an icing used to decorate or sculpt cakes and pastries. It doesn't have the texture of most icings: rolled fondant is "akin to modelling clay", while poured fondant is a thick liquid. The word is French for "melting", from the same root as fondue, and Wikipedia gives the English pronunciation as FON-dənt.
BBC Food describes the traditional method. Sugar, water and cream of tartar or liquid glucose are boiled together until the syrup reaches the soft ball stage, when a drop of syrup in cold water forms a soft ball you can roll between your fingers. The mixture is then kneaded into a smooth dough, and colourings or flavours such as peppermint, lemon or coffee can be added.
From there, fondant can be rolled into shapes to make sweets, poured warm into moulds and coated in chocolate, used to coat small fruits, or used to ice and decorate cakes, says BBC Food. Most home bakers never make it from scratch, though. As BBC Food's guide to icing a Christmas cake puts it, fondant is usually bought in ready-to-roll blocks.
Types of fondant
"Fondant" covers a few different products, which is why recipes can seem to contradict each other. Wikipedia points out that rolled fondant is not the same material as poured fondant.
| Type | What it is | Used for |
|---|---|---|
| Rolled (ready-to-roll) | Soft, pliable sugar dough | Covering cakes, simple models |
| Poured fondant | Boiled sugar syrup, kneaded or warmed to pour | Fondant fancies, sweet centres |
| Fondant icing sugar | Icing sugar with dried glucose syrup; add water | Glossy tops on cupcakes, sponges and tarts |
| Marshmallow fondant | Melted marshmallows, icing sugar and fat | Homemade rolled fondant |
| Sugar paste and gum paste | Firmer doughs that set hard | Figures, flowers, fine details |
From Wikipedia (Fondant icing, Sugar paste), BBC Food and Silver Spoon. Checked 14 November 2026.
The names overlap. Wikipedia's fondant page treats sugar paste as similar to rolled fondant but harder setting, which makes it better for bride and groom figures and larger flowers. Its sugar paste page says gum paste, also called flower paste, is firmer again because of added gums such as tylose or gum tragacanth, so it dries faster and harder for fine work. Wikipedia also lists sculpting fondant, a stiffer rolled fondant for modelling.
Fondant icing sugar is different again. It's a powder rather than a ready-made icing. Silver Spoon explains that it includes dried glucose syrup, which gives a smooth, glossy, soft finish for cupcakes, sponges or Bakewell tarts once you add water. For how it compares with plain and royal icing sugar, see our guide to whether icing sugar is the same as powdered sugar.
What fondant is made of
Wikipedia lists sugar, water, gelatine, vegetable oil or shortening and glycerol as the usual ingredients. In rolled fondant, gelatine (or agar in vegetarian recipes) and food-grade glycerine keep the sugar pliable and give it a dough-like consistency. Commercial, shelf-stable rolled fondant often consists mainly of sugar and hydrogenated oil, although other formulations use ingredients such as cellulose gum.
A typical UK pack looks like this. Renshaw's White 'Just Roll With It' Fondant Icing, made in the UK, lists:
- sugar and glucose syrup
- palm oil
- a humectant (E422, glycerol) to keep it soft
- an emulsifier (E471) and stabilisers (E415 and E466)
- a preservative (E202) and flavouring
Renshaw labels it suitable for vegetarians and vegans, and its allergy advice says it's made in a factory that handles nuts. Its nutrition panel shows 87g of carbohydrate per 100g, of which 82g is sugars, plus 6.7g of fat.
How fondant icing is used
Rolled fondant is best known for covering celebration cakes. Wikipedia says it's rolled out like a pie crust and laid over the cake to give a perfectly smooth surface, which suits complex shapes such as large ruffles and takes food colouring well. Wedding cakes were traditionally covered with marzipan or royal icing, but fondant has become more common, partly because of nut allergies, as it doesn't need almonds.
Covering a cake with ready-to-roll icing
BBC Good Food's guide to icing a Christmas cake follows these steps once the cake has a layer of marzipan:
- Dust the work surface and rolling pin with icing sugar.
- Knead the ready-to-roll icing to make it more pliable, then dust it with icing sugar too.
- Roll it out evenly, turning as you go, until it's about ½cm thick.
- Brush the marzipan-covered cake with a colourless alcohol such as vodka, or cold boiled water, to help the icing stick.
- Lay the icing over the back of the cake first, lower it down to the front and smooth it with the flats of your hands.
- Neatly trim away the excess icing. The cake is then ready to decorate.
Renshaw's pack instructions suggest rolling to 2 to 4mm thick and say that for best results the cake should first be coated with marzipan, buttercream or ganache. BBC Food's Christmas cake guide recommends a fairly thick layer of fondant over marzipan for the smoothest finish. You can skip the marzipan and brush the cake with warmed, sieved apricot jam instead, but the finish won't be as smooth, and oils from a fruit cake can leak out and discolour the icing over time. BBC Food suggests icing a Christmas cake between 24 hours and a week ahead.
Fondant also makes decorations. BBC Good Food's classic iced holly cake uses 850g of ready-to-roll icing to cover a 20cm fruit cake, then colours the rest red and green for berries and holly leaves.
Fondant fancies and sweets
Poured fondant is the glossy coating on small cakes. Wikipedia describes Mr Kipling French Fancies, launched in 1967, as small sponge cakes topped with a dome of buttercream and coated in fondant icing, and notes that supermarket and homemade copies are called fondant fancies. Fondant also turns up in sweets: CoFID, the UK's food composition dataset, has an entry for dark chocolate with crème or mint fondant centres, such as After Eights.
Fondant vs royal icing, buttercream and marzipan
All four can finish a cake, but they're made differently and behave differently.
| Icing | Made from | Finish |
|---|---|---|
| Rolled fondant | Sugar, glucose syrup, fat, glycerine | Soft, smooth, rolled sheet |
| Royal icing | Egg whites, icing sugar, lemon juice | Spread or piped; sets hard |
| Buttercream | Butter and icing sugar | Soft, spread or piped |
| Marzipan | Ground almonds and sugar | Smooth layer, often under icing |
From Wikipedia (Fondant icing, Royal icing), BBC Food (royal icing, icing) and Silver Spoon. Checked 14 November 2026.
Royal icing is a sweet, fluid paste of whisked egg whites, icing sugar and lemon juice that sets solid, says BBC Food, and it's the traditional covering for wedding and Christmas cakes. BBC Good Food's recipe uses 3 egg whites, 600g icing sugar and 1 teaspoon each of liquid glucose and lemon juice. BBC Food's Christmas cake guide says royal icing can look good even spread casually, and that it's less sweet than fondant. Adding 1 to 2 teaspoons of glycerine stops it setting too hard to cut.
Buttercream is made from butter and icing sugar, says Silver Spoon, and is soft enough to spread or pipe. Renshaw suggests it as a base coat under fondant.
Marzipan often goes under fondant or royal icing rather than replacing it, giving a flat surface and stopping crumbs or colour from the cake showing through. Read more in our guide to what marzipan is and how it's used. Wikipedia lists marzipan and mochi as alternatives to rolled fondant.
What fondant tastes like
Fondant is chosen for the way it looks. Wikipedia says its flavour and texture are generally considered a weak point, as it is sweet and chalky, and that rolled fondant is very sweet but not usually thought to taste good or have an appealing texture. Some bakers who use it even recommend against eating it, which is why you'll often see people peel it off a slice of cake.
Flavour can be added. BBC Food mentions peppermint, lemon and coffee, and Renshaw's ready-to-roll range includes a chocolate version.
Carbs in fondant icing
Fondant is mostly sugar, so it carries a lot of carbohydrate. CoFID lists homemade versions of several icings:
| Per 100g (CoFID) | Carbs | Sugars |
|---|---|---|
| Fondant icing, homemade | 90.1g | 88.9g |
| Royal icing, homemade | 93.4g | 92.4g |
| Glacé icing, homemade | 88.9g | 88.0g |
| Butter icing, homemade | 63.4g | 62.8g |
| Marzipan, retail | 67.6g | 67.6g |
| Fancy iced cakes, retail | 57.6g | 44.1g |
CoFID 2021 codes 17-804 (Icing, fondant, homemade), 17-805 (Icing, Royal, homemade), 17-583 (Icing, glace, homemade), 17-783 (Icing, butter, homemade), 14-875 (Marzipan, white and yellow, retail) and 11-839 (Cakes, fancy iced, individual, retail, including French and fondant fancies). Checked 14 November 2026.
Shop-bought rolled fondant is similar: Renshaw's white ready-to-roll icing lists 87g of carbohydrate per 100g. On that figure, the 850g used to cover the cake in BBC Good Food's classic iced holly cake comes to about 740g of carbohydrate, before the marzipan or the cake itself. That's our own calculation from the pack figure and the recipe quantity.
Is fondant icing keto?
No. With around 90g of carbohydrate per 100g, almost all of it sugar, traditional fondant doesn't fit a keto diet. For a keto bake, you could choose a different finish instead, such as a cream cheese icing, a ganache or a buttercream made with a powdered sweetener. Our guide to what to use instead of icing sugar explains how powdered sweeteners behave in buttercream, glacé icing and royal icing, and our keto Christmas cake is topped with homemade marzipan and a white icing made with a powdered sweetener.
Cake toppings with our products
If you'd rather finish a cake without sugar-based fondant, here's how our products could fit in, based on what each product page says.
- For buttercream and icing. Powdered Erythritol & Stevia Blend is erythritol with a touch of stevia, finely ground, in a 1kg pack. The product page says it replaces icing sugar 1:1 in frostings, glazes and buttercream.
- For a ganache coating. Keto Dark Chocolate Buttons are made with a minimum of 64% cocoa and sweetened with erythritol and stevia, in a 210g pouch. The product page suggests melting them into chocolate sauces and ganache. Our guide to what ganache is covers ratios and how to use it on cakes.
- For the cake underneath. Keto Chocolate Cake Mix is made up with 3 eggs, 100g melted butter and 1 tbsp water, baked in an 8 inch round tin and cut into 12 slices, or made into 12 cupcakes, according to the product page.
Product details are as shown on each product page. Free delivery on orders over £30.
Royal icing and royal icing sugar contain egg, and Silver Spoon notes that its icing sugars may contain traces of egg. Renshaw's fondant is made in a factory that handles nuts, and marzipan is made from almonds. The Keto Dark Chocolate Buttons product page says they contain sweeteners and that excessive consumption may cause a laxative effect. Always check the pack for full allergen information.
Key takeaways
- Fondant is a sugar paste for cakes. It's rolled out to cover cakes or poured over small cakes and sweets.
- Ready-to-roll icing is rolled fondant. It's what most UK bakers buy, in white or colours.
- It's mostly sugar and glucose syrup. With a little fat, glycerine and stabilisers to keep it pliable.
- It isn't royal icing. Royal icing is egg white and icing sugar, and sets hard.
- It carries a lot of carbs. 90.1g per 100g for homemade fondant in CoFID, and 87g on Renshaw's label.
Frequently asked questions
What is the difference between fondant and royal icing?
Royal icing is made from whisked egg whites, icing sugar and lemon juice and sets hard, says BBC Food. Rolled fondant is a soft, pliable sugar dough that's rolled out and draped over a cake for a smooth finish. BBC Food adds that royal icing is less sweet than fondant, and both usually go over a layer of marzipan.
Can you make fondant icing with normal icing sugar?
Traditional fondant isn't just icing sugar. BBC Food explains that sugar, water and cream of tartar or liquid glucose are boiled to the soft ball stage, then kneaded smooth. Fondant icing sugar is icing sugar with dried glucose syrup added, says Silver Spoon, and gives a glossy, soft finish when mixed with water.
What does fondant taste like?
Mostly of sugar. Wikipedia describes fondant as sweet and chalky and says its flavour and texture are generally seen as a weak point, so it's usually chosen for how it looks rather than how it tastes. Some bakers who use rolled fondant even recommend against eating it. Flavourings such as peppermint, lemon or coffee are sometimes added.
Is ready-to-roll icing the same as fondant?
Yes, in everyday UK baking they're the same thing. BBC Food says fondant is usually bought in ready-to-roll blocks that you roll out and smooth over the cake, and BBC Good Food recipes call for ready-to-roll white fondant icing. Renshaw, a UK brand, sells its ready-to-roll range as fondant icing in white and a range of colours.
Is fondant icing vegetarian?
It depends on the recipe. Wikipedia says rolled fondant includes gelatine, or agar in vegetarian recipes, to keep the sugar pliable. Renshaw's white ready-to-roll fondant icing is labelled suitable for vegetarians and vegans, and its ingredients list contains no gelatine. Check the pack, because recipes and brands vary, and homemade versions may use gelatine.
Sources
- Wikipedia. Fondant icing (definition, pronunciation, rolled and poured fondant, ingredients, types, taste, alternatives), Sugar paste (sugar paste and gum paste), Royal icing and Mr Kipling (French Fancies). Checked 14 November 2026.
- BBC Food. Fondant icing, Royal icing, Icing and How to ice a Christmas cake the easy way. Checked 14 November 2026.
- BBC Good Food. How to ice a Christmas cake, Classic iced holly cake and Royal icing (ingredients and method). Checked 14 November 2026.
- Silver Spoon. What is the difference between icing sugars? (buttercream, royal icing and fondant icing sugar, allergen note). Checked 14 November 2026.
- Renshaw. White 'Just Roll With It' Fondant Icing (ingredients, instructions, allergy advice, typical values per 100g). Checked 14 November 2026.
- Public Health England / Office for Health Improvement and Disparities. Composition of foods integrated dataset (CoFID) 2021 (codes 17-804, 17-805, 17-583, 17-783, 14-875, 11-839 and 17-650). Checked 14 November 2026.
- Groovy Keto product pages: Powdered Erythritol & Stevia Blend, Keto Dark Chocolate Buttons and Keto Chocolate Cake Mix (ingredients, sizes, method and label lines as shown). Checked 14 November 2026.
