Preparation Beat together all ingredients except food coloring in a large bowl with an electric mixer at moderate speed until just combined, about 1 minute. Increase speed to high and beat icing, scraping down side of bowl occasionally, until it holds stiff peaks, about 3 minutes in a standing mixer or 4 to 5 minutes with a handheld. Beat in food coloring (if using). If you plan to spread (rather than pipe) icing on cookies, stir in more water, 1 teaspoon at a time, to thin to desired consistency.
Preparation Beat together all ingredients except food coloring in a large bowl with an electric mixer at moderate speed until just combined, about 1 minute. Increase speed to high and beat icing, scraping down side of bowl occasionally, until it holds stiff peaks, about 3 minutes in a standing mixer or 4 to 5 minutes with a handheld. Beat in food coloring (if using). If you plan to spread (rather than pipe) icing on cookies, stir in more water, 1 teaspoon at a time, to thin to desired consistency.