There exist two main factions in the iced coffee wars. The traditionalists make hot coffee, then refrigerate it until it’s cold. Cold brewers soak coffee grounds in cold water; because the water isn’t hot, the brewing process takes longer, but the lower temperatures supposedly make for less acidic coffee. (There are some nihilists—mostly dads—who pour hot coffee over ice, resulting in lukewarm coffee-water. Everyone else agrees this is terrible.)

Is cold brew better than old hot coffee that’s been refrigerated? Cold brew partisans say that refrigerated hot coffee turns stale and bitter, just as regular coffee does when left on the burner all day. Cold brew opponents say it tastes like chocolate-flavored arsenic. I say they’re both right. But the real problem with these methods is that they require hours—even a full night—of forethought. You shouldn’t have to make tomorrow’s iced coffee today. With my technique you don’t have to.

All you need to make the best iced coffee is something you should already have: an ice cream maker. And actually, you just need the insulated freezer bowl that comes with the machine. (Imagine a bowl made out of ice packs and coated in metal.) If you've used an ice cream maker before, you know you pour a chilled base (milk, cream, whatever) into the frozen bowl, and as the liquid swirls against the bowl's walls, it freezes. One day, while debating sticking my coffee pot in my freezer with the hope that it might cool quicker, I saw the ice cream bowl and realized the same principle would work for iced coffee.

There is a whole Shark Tank season's worth of gadgets for making iced coffee, from tarted-up mason jars to overpriced "Hyperchillers" capable of cooling a paltry 12 ounces at a time. But none of these also make ice cream, which is important, because bringing a takeout container of homemade is an unbeatable dinner party move.

So keep the ice cream bowl in your freezer. (Where else would you keep it?) The next time you want iced coffee, simply make hot coffee however you prefer—drip, pour over, French press, whatever. Pour the coffee into the frozen bowl, wait a minute or so, give it a few swirls, and you’ll have cold coffee. (Because the coffee starts hot, rather than chilled, like an ice cream base, it won’t freeze.) Pour it into a cup of ice, and voilà: nearly instant iced coffee that is neither bitter and flat nor watered down. When you’re done, give the bowl a rinse, and stick it back in the freezer. Enjoy the thrill of spontaneity and the taste of regular coffee, except cold.