Dissolve the Egg White Protein in the water and lemon juice, then whip with an electric mixer until frothy and light.

Add the erythritol and beat until all the erythritol is dissolved and the icing is smooth, and thick. The icing should fall in ribbons from a spoon or beater, standing on the surface of the icing in the bowl for a few seconds before melting back in.

Add the vanilla extract and stir well. If the icing is too thick to pipe, add more water 1/4 tsp. at a time until it reaches the desired consistency.

Add gel food coloring of choice in small amounts, using the tip of a toothpick to add a dab at a time until the desired color is reached. Try white gel icing coloring for a snow-white look to the icing.

Use icing immediately, as it will dry to a hard finish.