It's a pour over method [1] You can also use a regular drip machine though. Use half the normal water. Add the equivalent ice (by weight) to the flask. Brew as

It's a pour over method [1] You can also use a regular drip machine though. Use half the normal water. Add the equivalent ice (by weight) to the flask. Brew as normal, but turn it off as soon as it's finished. The slow drip of hot coffee is cooled immediately as it hits the ice. Since the brewed coffee is cold, you can add extra ice to your cup without it melting and diluting the taste too much. Adjust the water / ice ratio as desired. [1] https://www.youtube.com/watch?v=Y3jxJv5UiPg https://www.youtube.com/watch?v=Y3jxJv5UiPg