How to Make Japanese Flash Iced Coffee, Cold Brew Coffee and Iced Tea

How to Make Japanese Flash Iced Coffee, Cold Brew Coffee and Iced Tea

It’s hot. It’s going to get hotter. And more and more you’ll be craving delicious iced cold coffee to reinvigorate that afternoon summer fatigue.

Chances are you’ve heard of cold brew coffee by now. It’s become a standard in specialty coffee houses around the globe. You can even find pre-packaged cold brew at your local grocery store. Today, we thought we’d show you a few other delicious ways to make iced coffee at home as well as a simple way to make cold brew iced tea.


Want to hear something shocking? Many specialty coffee professionals despise cold brew. Like, they really really hate it. Why? The essence of cold brew — what makes it unique — is that the coffee never contacts hot water. Typically, cold brew is made with a 12-24 hour steep in ice water. Because coffee contains desirable solubles and volatile aromatics that are only released at higher or “hot” temperatures, they don’t stand a chance making it into your cup of cold brew. Thus, for some folks cold brew lacks the nuance of a traditional cup of coffee. Cold brew fans love it for this fact and describe it as “smooth” and “rich” the haters would call it “flat” and “lackluster”.

While we understand both sides of the cold brew argument, we’re going to show you a simple way to make iced coffee that many feel maintains flavor nuances found in coffee brewed hot. It’s called “flash brew”, a technique developed in Japan and gained popularity in the states through the efforts of Peter Giuliano and others. This method utilizes hot water that’s brewed directly over ice. And because flash-brew uses hot water, we’re able to extract all that aromatic goodness and use ice to lock it into our beverage. The result is an amazingly lively cup of iced coffee. Is it better than cold brew? We’ll let you be the judge.


Flash brew is commonly made by the cup with some sort of pour-over apparatus like a Chemex or Hario v60. We prefer our new Temple Pro Cone dripper. If you need to brush-up on your pour-over skills, check out our tutorial video here.

We’re going to follow all of the standard, run-of-the-mill steps of a pour-over with one exception: we’re going to replace half our brewing water with ice. For example, if you typically brew with 400g of hot water to 28g of coffee, you’d replace 200g of that water with ice, and brew directly on top of that.

Pretty neat, yeah? We’re going to show you a recipe for a 12oz cup, but we’ll also be providing different size recipes at the end of this article. Let’s get right to it.

STEP ONE:  Measure 170g of ice into a range server or large mug.

STEP TWO:  Measure 24g of coffee and grind medium-fine (table salt size or setting 16-18 on Baratza style grinder). Place coffee into brewing device, set atop decanter and scale. Tare scale.

STEP THREE:  Pour just enough water to saturate the grounds (30-50g). Let sit for 30-40 seconds, until it stops bubbling.

STEP FOUR:  Pour water in 40-50g increments, starting in the center and spiraling outward in small circles. Pause 15-20 seconds between pours. Pour until you reach 170g total.

STEP FIVE:  Pour into your favorite cup and enjoy tasty, tasty iced coffee.

Additional Recipes:

12oz: 24g medium-fine coffee, 170g ice, 170g water.

16oz: 32g medium-fine coffee, 225g ice, 225g water.

20oz: 40g medium-fine coffee, 280g ice, 280g water.

PRO-TIP:  To keep it simple, we divided the water and ice 50-50. But this can be modified in favor of more brewing water and less ice. Many of us here at Temple enjoy a 1/3 ice to 2/3 water formula. So for a 12oz cup, you’d use 100g ice and 240g brewing water. Experiment and see what works best for you.


Last year, we introduced the Cold Bruer: a brand new slow-drip cold brew device. Like we mentioned before, cold brew is typically made by letting ground coffee sit in ice water for very long periods of time (12-24 hours). It’s similar to a French Press, and produces a similar cup: rich and full-bodied. The Cold Bruer and it’s drip valve system allows water to drip slowly through a bed of coffee over a period of about 4-5 hours. It produces a more nuanced, complex and extremely tasty cold-brew experience. Plus, it looks super classy on your countertop. For more, check out our Cold Bruer tutorial video:


Maybe your significant other dislikes coffee. Mine does. It’s a tragedy, yes. But tea can be a delicious alternative. And you can even cold brew it. It’s really, really easy. We’ll be using our Hario Iced Tea Pitcher (on sale), but you can use anything with a simple filtration system (like a French Press).

STEP ONE:  Add tea. We’re using 1 heaping tablespoon per cup.

STEP TWO:  Add cool water.

STEP THREE:  Secure lid and place in refrigerator for 6-8 hours.

STEP FOUR:  Strain and enjoy.

PRO-TIP:  Different teas will extract at different rates. Taste a small sample at 6 hours. If it’s too weak for your liking, taste again at 7 hours. Repeat until desired taste is achieved.

There we have it, folks. Three ways to keep cool this summer. Let us know your results in the comments below.

Items Featured in this Article:

Temple Pro Cone Dripper

Hario Glass Range Server

Bonavita Electric Gooseneck Kettle

Acacia Bluetooth Barista Scale

Temple KeepCup

Cold Bruer

Hario Iced Tea Pitcher