Ingredients:
- 2 cups (240 g) Icing Sugar (Powdered Sugar), sieved
- 3-4 Tablespoons (45-60 ml) Whole Milk (or filtered water)
- 1 teaspoon (5 ml) Clear Vanilla Extract
- 1/2 teaspoon (2.5 ml) Fresh Lemon Juice
- Pinch (1 g) Fine Sea Salt
- Gel Food Colouring (optional, as needed)
Instructions:
- Sieve the Sugar: Place a fine mesh sieve over the mixing bowl. Sift the entire measure of icing sugar into the bowl. This step is crucial for a smooth, lump-free glaze.
- Combine Flavoring: In a separate small bowl, combine the vanilla extract, lemon juice, salt, and 3 tablespoons (45 ml) of the milk.
- Mix: Pour the wet mixture into the centre of the sieved sugar. Using a whisk or a hand mixer on the lowest speed, gently combine until a thick, paste-like icing forms. Scrape down the sides of the bowl.
- Test Consistency (Outlining): If using for outlining or thick detail, the icing should follow the '15-second rule' (take 15 seconds to disappear entirely when cut). If too stiff, add the remaining milk slowly, half a teaspoon at a time, until the desired outlining consistency is achieved.
- Divide and Thin: Transfer about one-third of the stiff icing (the 'outlining consistency') into a separate container or piping bag. This portion is reserved for the borders.
- Adjust the Flood Consistency: Add 1-2 teaspoons (5-10 ml) of milk or water to the remaining bulk of the icing. Stir well.
- Test Consistency (Flooding): The flood icing should be runnier, following the '5-8 second rule' (the surface should flow back together and disappear completely in 5-8 seconds). Adjust liquid drops at a time if necessary.
- Colour (Optional): If coloring, divide the prepared icings (outlining and flooding) into smaller bowls. Add concentrated gel food coloring sparingly using a cocktail stick. Mix thoroughly until the color is uniform.
- Apply Outlines: Transfer the thicker (15-second) icing to a piping bag. Pipe an outline or 'dam' around the edge of the cooled biscuit. Allow this outline to set for 15-20 minutes before filling.
- Flood and Smooth: Use the thinner (5-8 second) icing to fill the outlined area. Use a clean toothpick or scribe tool to gently push the icing into the corners and pop any air bubbles.
- Dry: Allow the decorated biscuits to dry completely at room temperature, ideally overnight (12-24 hours), until the glaze is hard to the touch for stacking and transport.