How to Make Flash Brew Coffee (a Better Way to Do Iced Coffee)
The Step-by-Step Guide to Making Flash Brew Coffee
Let’s be honest: most homemade iced coffee is… not great. It’s often bitter, watery, or both. You pour hot coffee over ice, it dilutes instantly, and you’re left with a sad, lukewarm disappointment.
Enter: flash brew.
This is the iced coffee method you’ve been missing.
What Is Flash Brew Coffee?
Flash brew—also known as Japanese iced coffee—is a method where you brew hot coffee directly over ice. The hot water extracts all the flavor, and the ice rapidly chills it, locking in brightness and aroma without watering it down.
Why Flash Brew Is Better
- Tastes brighter and fresher – preserves acidity and aromatics
- Fast – no 12-hour steeping like cold brew
- No bitterness – prevents over-oxidation
What You’ll Need
- Fresh Cape House Coffee (Golden Hour Espresso or New England Morning Blend are perfect)
- A pour-over setup (like a Chemex or V60)
- Hot water (about 200°F)
- Ice
- Mug or carafe
- Optional: kitchen scale for precision
Flash Brew Ratio
For a single 12oz cup:
- 30g coffee
- 210g hot water
- 120g ice in your carafe or mug
This may look like a 7:1 ratio (because of the hot water), but once you factor in the ice that melts during brewing, your actual brew strength lands around 11:1 to 12:1—right in the sweet spot for iced pour-over.
Keep the total water (hot water + ice) close to 330g to maintain a balanced brew. Adjust as needed—but always keep the water-to-ice balance in check.
How to Brew
- Add ice to your carafe. This is where the coffee will drip and chill immediately.
- Set up your pour-over with coffee grounds. Use a medium grind.
- Start pouring. Bloom with 60g water, wait 30 seconds, then continue pouring slowly until you reach 210g.
- Let it finish dripping, then swirl gently.
- Serve over fresh ice (optional) and enjoy immediately.
Bonus Tips
- Filtered water = better flavor
- Flash brew works especially well with light and medium roasts
- Add a little vanilla cold foam on top and some cinnamon for a sweet finish
Final Sip
If you’ve been disappointed by homemade iced coffee, this is your fix. It’s bright, bold, and chilled to perfection—ready in minutes.
Tried it? Snap a pic and tag us @capehousecoffeellc so we can see your summer brew in action!