Preheat the oven to 100°C (212°F) fan force. Line one large baking tray with greaseproof paper.
If you are using whole eggs, separate the whites from the yolks carefully. Ensuring there is no yellow left in the whites.
Place egg whites into a bowl of a stand mixer fitted with a wire whisk attachment. Beat at low speed until air bubbles start forming then increase the speed to medium speed. Beat until soft peaks form.
Add the castor sugar to the egg whites one tablespoon at a time, with the mixer running at medium-low speed. Continue until all of the sugar has been added.
Add the vinegar to the meringue mixture and increase the speed of the mixer to medium-high speed, beat for 10 minutes until stiff peaks form.
Add the lemon juice and lemon zest to the meringue mixture and beat briefly until combined.
Add two drops of food coloring to the meringue and fold this through with a rubber spatula. Don’t over mix as you should keep the swirls of yellow.
Fill a disposable piping bag fitted with a round nozzle with the meringue mixture. Pipe meringue kisses onto the prepared cookie sheet, the diameter of each meringue should be about 3cm (1.2 inches).
Bake in a preheated oven for 15 to 20 minutes or until the bottom of the mini meringues lift easily off of the parchment paper. Turn the oven off and allow the meringues to cool in the oven overnight. Enjoy!
Notes
Before whisking the whites, wipe your bowl and whisk with lemon juice to ensure there is no fat on either. Then wash them in very hot water.