Superfine Sugar
Superfine sugar (called caster sugar in the UK) is granulated sugar that has been ground into much smaller crystals, but it's still 100% sucrose with no starch added, unlike powdered sugar. The finer grain dissolves almost instantly in liquid and batter, which matters most in meringues, cold drinks, and delicate cakes where undissolved sugar grains would leave a gritty texture or weigh down whipped egg whites.
Varieties
Superfine sugar and caster sugar are the same product with different regional names. Powdered sugar (confectioners' sugar) is a separate product entirely, ground even finer and mixed with cornstarch as an anti-caking agent, which changes both texture and how it behaves in baking.
Buying tips
Look for it labeled 'superfine' or 'baker's sugar' in the baking aisle; in UK products it's sold as 'caster sugar.' If unavailable, making your own from granulated sugar at home takes under a minute and costs nothing extra.
Substitutes
Granulated sugar, processed in a food processor or blender — 1:1 by weight
Pulse for 30-60 seconds until it looks like fine sand. This is the closest match and works in almost any recipe calling for superfine sugar.
Regular granulated sugar — 1:1
Fine for cookies, cakes, and anything creamed with butter or baked long enough to dissolve; not recommended for meringues or cold beverages where grittiness will show.
Powdered (confectioners') sugar — 1.75:1
Contains cornstarch and dissolves too readily, which can make baked goods slightly denser or gummy; best only for icings, whipped cream, or drinks, not for structure-dependent baking like meringue.
Caster sugar — 1:1
This is the same product under a different name, common in UK and Australian recipes; no adjustment needed.
Storage
Store in an airtight container at room temperature, away from moisture. Properly sealed, it keeps indefinitely since sugar doesn't spoil, though it can clump if exposed to humidity.
How to use
Best in recipes where sugar needs to dissolve quickly and completely: meringues, macarons, mousses, whipped cream, cold cocktails and iced drinks, angel food cake, and delicate sponge cakes. Its fine crystals also cream more smoothly with butter, giving a slightly lighter texture in some cookies.
What it pairs with
Used in the same contexts as granulated sugar, particularly egg whites (meringues, souffles), cream (whipped cream, mousse), and cold liquids (lemonade, cocktails, iced tea) where quick dissolving prevents graininess.
Nutrition
Nutritionally identical to granulated sugar, about 16 calories per teaspoon with no vitamins, minerals, or fiber. The finer grind doesn't change sugar content, only texture and how quickly it dissolves.
FAQ
Can I make superfine sugar at home?
Yes. Pulse regular granulated sugar in a food processor for 30-60 seconds until it turns into fine, sand-like crystals. Let dust settle before opening the lid.
Why do meringue recipes specifically call for superfine sugar?
Meringues rely on sugar dissolving fully into whipped egg whites; coarser granulated sugar crystals take longer to dissolve and can leave the meringue grainy or cause it to weep syrup after baking.
Is superfine sugar sweeter than regular granulated sugar?
No, sweetness is identical gram for gram. The only difference is crystal size, which affects dissolving speed and mouthfeel, not sweetness.
Can I use superfine sugar in place of granulated sugar in any recipe?
Yes, it works as a 1:1 swap in virtually everything, including cookies, cakes, and sauces, since it's the same sugar just ground finer.
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