- take a deep-bottomed pan and put it over medium flame.Add full fat milk in it along with powdered sugar and mix well. Once mixed, lower the flame and simmer the milk for a 2-3 minutes, until sugar is dissolved completely. Let the milk simmer for about 20-30 minutes until the milk is reduced by half and thickened. Once the condensed milk is ready, turn off the flame and let it cool down at room temperature. Transfer to a jar and close with a airtight lid.