I have watched enough coffee trends come and go to fill a notebook. Dalgona whip, butter coffee, olive oil in your espresso. Every possible thing you can do to a cup of coffee has had its moment on social media. Most of them, you try once and you forget. But every now and then something surfaces that actually makes sense. The latest one involves a Ziplock bag and a little bit of patience.

The idea is simple, and maybe that is why it works. You brew your favorite coffee, pour it into a Ziplock bag, seal it tight, and freeze it. What comes out is somewhere between a slushie and a granita. That beautiful Italian semi-frozen dessert I grew up eating in the summers outside Naples. You squeeze the bag a few times as it freezes to break up the ice crystals, and the result is this slushy, deeply coffee-forward drink that tastes like it cost nine dollars at a café.

My grandmother would have looked at the Ziplock bag with suspicion. She froze her coffee in small glass containers and scraped it with a fork every hour, the proper way, the way that gives you control over the texture. But the spirit is the same. You are taking something good and making it refreshing without burying it under seventeen pumps of vanilla syrup and a mountain of whipped cream.

What I like about this trend, and you can read the full breakdown here at AOL, is that it treats coffee like what it should be in August: cold, simple, and not too sweet. Too many of these viral drinks pile on flavors until you cannot taste the coffee anymore. This one lets the brew do the talking. Use good coffee and you will taste it. Use terrible coffee and you will taste that too.

A few things I would tell you if you want to try it. Brew the coffee a little stronger than you normally would, because freezing dulls flavor. If you take sugar, add it while the coffee is hot so it dissolves completely. And do not fill the bag more than halfway, or it will burst at the seam and you will have a mess in your freezer that your wife will remind you about for weeks.

The best food and drink ideas are the ones you can make with what you already have in your kitchen. This qualifies. A bag, some coffee, a freezer. No special equipment, no expensive gadgets. Just care and a little patience. Which is really all good food has ever needed.