How do I get royal icing to the right consistency?

The reason royal icing frustrates people is that recipes give a quantity of water, and the correct quantity depends on the icing sugar, the egg white, the humidity and the job. Working by the seconds test instead makes it repeatable: you are measuring the icing's behaviour rather than trusting a number. The drawing shows the three consistencies with a ribbon falling from a spoon in each, and the adjustment scale beside them.

What you'll need

• Sifted icing sugar
• Egg white or meringue powder
• Small bowls and a damp cloth
• A teaspoon and a spray bottle of water (optional)

Step by step

1. Sift the icing sugar. Always.Icing sugar clumps and a single lump will block a piping nozzle at the worst moment. Sift it even if the packet says it is already sifted.
2. Make the whole batch stiff first.Beat to the stage where it holds a firm peak that does not fall over. This is your base — it is far easier to let icing down than to stiffen it, because stiffening means adding sugar and changing the volume.
3. Divide into bowls before colouring or thinning.One bowl per consistency and colour. Cover each with a damp cloth or cling film touching the surface — royal icing crusts within minutes of being exposed.
4. Let down with water, a few drops at a time.A teaspoon, or better a spray bottle. Stir gently rather than beating, because beating adds air bubbles that show up as pits in a flooded surface. Half a teaspoon changes a small bowl noticeably.
5. Test with the seconds count.Lift a spoonful and let the ribbon fall back. Outline consistency: the ribbon sits on the surface for about fifteen seconds before merging. Flood consistency: it disappears in five to ten. Count it rather than guessing.
6. Outline first, then flood inside it.The stiffer outline is a wall that holds the thinner flood icing. Let the outline crust for ten to fifteen minutes before flooding, or the flood will breach it.
7. Pop the bubbles.After flooding, tap the biscuit gently on the worktop and pop any surface bubbles with a cocktail stick within the first minute, while the icing can still level itself.
8. Dry properly before stacking.Six to eight hours at room temperature for flooded biscuits, longer in humid weather. A dehumidified room or a fan on low speeds it up. Never dry royal icing in the fridge.

Tips

• Meringue powder or pasteurised dried egg white is the practical choice over raw egg white — it is more stable, keeps longer, and removes the raw egg question entirely for a decoration that will sit out for days.
• Glycerine keeps royal icing softer so it can be cut rather than shattering. Leave it out entirely for piped decorations that need to set rock hard.
• Gel colours, not liquid. Liquid colouring adds water and moves the consistency as you colour.
• Royal icing keeps for a week in an airtight container in the fridge. Bring it to room temperature and re-beat briefly before use.

Common mistakes

• Adding water by the teaspoon rather than by drops — A teaspoon can take a bowl straight past flood consistency to unusable. You then need a large amount of sugar to bring it back and you have twice as much icing as you wanted.
• Leaving bowls uncovered while you work — A crust forms in minutes and the fragments then block nozzles and show as lumps in a flooded surface. Damp cloth on every bowl.

If it doesn't work