Heat the swollen gelatin with sugar over low heat to a liquid state, but do not bring it to a boil, but let it cool down a little. Gelatin and sugar should completely dissolve. To do this, it is necessary to mix more often.
Pour the hot gelatin mixture into the whipped whites, stirring constantly, in a thin stream. Continue whisking for another 5-10 minutes until the mixture cools down to room temperature.