Pour the egg whites into a clean, grease-free, heatproof bowl with plenty of extra room - the cream turns out quite voluminous. Whip with a mixer until lightly foamy.

Add all the sugar and the citric acid and whip with the mixer until smooth, no more than a minute.

Set the bowl over simmering water so it doesn't touch the water, and whip on high speed for 8-10 minutes. The mixture will triple or quadruple in volume and become firm and springy.

Remove the meringue from the heat and keep whipping for another couple of minutes to cool it down. The finished cream is springy, holds together, and curls neatly around the whisk. Tint with gel food coloring if desired.

Transfer the cream to piping bags fitted with tips and decorate as desired. White cream holds its shape longer than tinted cream.