True ice coffee is cold brewed! Here's a perfect cup of ice coffee for your reference. You may add a tablespoon of condense milk to make it Vietnamese style.
For 6 ounces of iced coffee:
1. In a small pitcher or 1-quart measuring cup, whisk together 1/3 cup ground coffee and 1 1/3 cups cold water until all the lumps are gone.
2. Cover tightly and refrigerate for at least 5 hours, but it's best left overnight (not much longer or it'll get bitter).
3. Strain the coffee through a coffee filter-lined strainer set over a tall glass of ice, pushing it through with a spatula.