It can take up to 5 minutes for the meringue to get stiff peaks, but it depends on the method and equipment you use. My perfect method for stiff peaks is - Use a stand mixer, start at medium speed, and whip until the eggs are foamy - about two minutes. Then, add egg whites slowly, one tablespoon at a time (this should take about a minute). Once all the sugar is in, turn the mixer to medium-high and whip for three full minutes. This should give you perfectly stiff meringue.