Caster sugar (also called superfine sugar) is a fine, quick dissolving white sugar that sits somewhere between regular granulated sugar and icing sugar, and it's in almost every Aussie baking recipe. It's the secret to a fluffy Lemon Meringue Pie and silky Chocolate Mousse, and if you can't find it, you can make your own in 2 minutes.
A Quick Look At The Recipe
✅ Recipe Name: How To Make Caster Sugar
🕒 Ready In: 2 minutes
👪 Makes: 1 cup (200g)
🍚 Calories: about 16 calories per teaspoon
🥣 Main Ingredients: granulated sugar
📖 Also Called: superfine sugar, castor sugar, baking sugar or baker's sugar
⭐ Why You'll Love It: No caster sugar in the pantry? Blitz regular sugar in a food processor, blender or Thermomix and you're ready to bake!
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What Is Caster Sugar?
Caster sugar is granulated sugar with much smaller crystals, so it dissolves really quickly. The texture sits between regular granulated sugar and powdered (icing) sugar.
Here in Australia, New Zealand and the UK it's a pantry staple, and we use it in almost all of our baking: cookies, slices, cakes and desserts. In other parts of the world it's less well known, which is why it's one of the questions I get asked most by readers!
Other Names For Caster Sugar
Depending on where you live, you might see caster sugar called:
- Superfine sugar: the most common name in the US.
- Castor sugar: just a different spelling of the same thing.
- Baking sugar or baker's sugar.
- Casting sugar.
Fun fact: caster sugar gets its name from the 'caster', a traditional kitchen shaker that was used to sprinkle sugar over fruit and desserts.
Jump to:
- A Quick Look At The Recipe
- What Is Caster Sugar?
- Other Names For Caster Sugar
- Homemade Caster Sugar Ingredients
- Types Of Caster Sugar
- How To Make Caster Sugar
- Top Tip
- Caster Sugar Vs Granulated Sugar
- Caster Sugar Vs Icing Sugar
- Uses For Caster Sugar
- Caster Sugar Substitute
- Caster Sugar Nutrition
- How To Store Caster Sugar
- Recipe Tips
- Caster Sugar FAQs
- Popular Recipes Using Caster Sugar
- How To Make Caster Sugar
Homemade Caster Sugar Ingredients
You only need one ingredient to make your own caster sugar at home:
Note: Scroll to the recipe card at the bottom for the ingredients quantities and full detailed method.
- Granulated sugar: regular white sugar or raw sugar both work. You'll also need a food processor, blender or Thermomix.
Types Of Caster Sugar
- White (regular) caster sugar: when a recipe just says 'caster sugar', this is the one it means. It's the most popular type and the easiest to find.
- Golden caster sugar: made from unrefined sugar cane or beets, so it keeps some of the molasses. It has a light brown colour and a subtle buttery caramel flavour. It's easier to find in the UK, and you can swap it for regular white caster sugar.
- Homemade caster sugar: made by blitzing granulated sugar. The grains won't be as even as store bought, but it's perfectly fine for baking.
How To Make Caster Sugar
Making your own caster sugar takes about 2 minutes. Here's how (the full recipe card is below):
Note: Scroll to the recipe card at the bottom for the ingredients quantities and full detailed method.
- Step 1: Add the sugar. Place the granulated sugar into a food processor, blender or Thermomix.
- Step 2: Blitz. Use the pulse or blend function until the sugar looks like very fine grains of sand. In a Thermomix, press Turbo for 1 second at a time.
- Step 3: Store. Pour the caster sugar into an airtight container and keep it somewhere cool and dry.
Top Tip
Blitz in short bursts and check as you go. You want the sugar finer than granulated sugar but not as fine as icing sugar, so stop once it looks like very fine sand.
Caster Sugar Vs Granulated Sugar
They're not the same. The crystals in caster sugar are much more finely ground than regular granulated sugar, so caster sugar dissolves when you mix it. That makes it the best choice for whipped cream, meringues, creamed butter mixtures, souffle and sponge cakes.
You can bake with caster sugar exactly the same way you'd use regular white sugar. There's no need to sift it, just measure and add it to your mixture.
Caster Sugar Vs Icing Sugar
Icing sugar (also called powdered sugar or confectioners' sugar) is much more finely ground than caster sugar. It's quite literally powdered sugar!
- Pure icing sugar has no anti caking agent, so it clumps easily and needs sifting. It also sets firmer.
- Icing sugar mixture is the most common type. It contains a little anti caking agent, such as cornflour, which stops it clumping, but it doesn't set as firm.
Uses For Caster Sugar
Because it dissolves so quickly, caster sugar is used in:
- Meringues: including lemon meringue pie, pavlovas like my Passionfruit Mango Pavlova, baked Alaska and meringue trifles.
- Sweetened whipped cream and chocolate mousse.
- Cookies and shortbread: it dissolves quickly when creamed with butter. Try my Jam Drops.
- Cakes and sponge cakes: like my Raspberry and Cream Jelly Cakes.
- Sauces: such as caramel or butterscotch sauce.
- Drinks: it can replace simple syrup in cocktails and mocktails, like my Pornstar Martini.
- Souffle.
Caster Sugar Substitute
The best substitute for caster sugar is to make your own (see the recipe card below). If a recipe calls for golden caster sugar, you can use regular white caster sugar instead.
Caster Sugar Nutrition
Caster sugar is similar to granulated sugar. It's fat free and cholesterol free, and each teaspoon has about 16 calories and 4.2 grams of carbohydrates, with no protein or fibre. Like all sugars, enjoy it in moderation.
How To Store Caster Sugar
Store caster sugar in an airtight container at room temperature, somewhere cool and dry, away from heat and moisture. Stored well, it technically never spoils, but it's recommended to use it within two years.
Small lumps mean it's been exposed to moisture. It's still fine to use, just remove the lumps.
Recipe Tips
- Use white or raw sugar: either works for homemade caster sugar.
- Pulse, don't over blend: stop when it looks like fine sand, before it turns to icing sugar.
- Thermomix: use Turbo for 1 second at a time.
- Keep it airtight: moisture causes lumps.
Caster Sugar FAQs
No. The crystals in caster sugar are much more finely ground than regular granulated sugar, so it dissolves easily. It is perfect for whipped cream, meringues, creamed butter mixtures, souffle and sponge cakes, and can replace simple syrup in cocktails and mocktails.
No. Icing sugar (also called powdered sugar or confectioners' sugar) is much more finely ground than caster sugar. Icing sugar mixture also contains a little anti caking agent, such as cornflour.
Caster sugar is also called castor sugar, superfine sugar, baking sugar, baker's sugar or casting sugar.
Caster sugar gets its name from a traditional kitchen shaker called a 'caster', which was used to sprinkle sugar on top of fruit and desserts.
Caster sugar is used in baking and desserts because its fine texture dissolves when mixed. It is also used to sweeten cocktails and mocktails, often in place of simple syrup.
Store it in an airtight container at room temperature in a cool, dry place away from heat and moisture. It technically never spoils, but it is recommended to use it within two years.
In Australia, New Zealand and the UK, you will find caster sugar in the baking aisle of any supermarket. In the US it can be harder to find, so try a specialty grocer, a baking supplies store or online, or make your own.
In the US, caster sugar is most commonly called superfine sugar.
In Australia it is simply called caster sugar. It is a pantry staple and you will find it in the baking aisle of every supermarket.
Yes! Add granulated sugar to the bowl and press Turbo for 1 second at a time until it looks like very fine sand.
The best substitute is homemade caster sugar. Simply blitz granulated sugar in a food processor, blender or Thermomix until it looks like very fine sand.
Its fine texture dissolves when mixed with other ingredients. For example, when butter and caster sugar are creamed together for cookies, the sugar dissolves into the butter.
Lumps mean the sugar has been exposed to moisture. It is still fine to use, simply remove the lumps.
Caster sugar tastes just like white sugar, but it has a finer texture and dissolves easily on the tongue.
Caster sugar is made from granulated sugar that has been processed to a finer texture.
Popular Recipes Using Caster Sugar
Now that you know all about caster sugar, here are a few of my favourite recipes to use it in!
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How To Make Caster Sugar
Ingredients
- 1 cup (200g) granulated sugar regular white or raw sugar
Instructions
- Place the granulated sugar into a food processor, blender or Thermomix.
- Use the pulse or blend function to pulverise the sugar granules until they resemble very fine grains of sand. If using a Thermomix, press the Turbo function for 1 second at a time.
- Pour the caster sugar into an airtight container and store in a dry, cool place.
Rita says
I loved the recipe for 100 cookies. I always wondered why Mum had an endless supply of cookies and said it was the biscuit fairy who delivered them. Thank you