Japanese iced coffee is made using a rapid cooling method that cools hot coffee in a short amount of time.

In the hot summer, you're more likely to order iced coffee than hot coffee at a coffee shop.
Iced coffee is likely to sell better than hot coffee in the summer for coffee shops as well.
There are two types of iced coffee: the gold brew method, which uses water to extract the coffee over a long period of time, and the rapid-chill method, which involves quickly cooling hot coffee at around 90 degrees Celsius with ice to make it iced. In Japan, the rapid-chill method is the most common.
The rapid-chill method was invented as one of the menu items when coffee shops began to appear in Japan during the Meiji period, and was called chilled coffee.
Chilled coffee is sometimes shortened to ``hiyashi-ko,'' and is still sometimes called ``hiyashi-ko'' in some coffee shops in Osaka.
Since the ice dilutes the coffee in rapid-chilled iced coffee, dark roast beans are best for a bitter and rich flavor. For bitterness and richness, beans from Brazil or Indonesia are suitable.

For a refreshing taste with acidity and fruitiness, medium roasts from Ethiopia or Kenya are recommended.