Koridashi: The Japanese Ice-Brew Method Your Summer Needs

If you’re a tea lover, there’s no better way to savor the heat and sunshine of summer than with Koridashi. This traditional Japanese brewing method involves a simple but elegant twist: instead of steeping tea leaves in hot water or even cold water, you let ice melt slowly over them.

The result is a smooth, flavor-packed tea with almost zero bitterness and a natural sweetness that’s perfect for warm weather. If you’ve never tried Koridashi before, this guide will walk you through what it is, why it works, and how you can enjoy it all summer long.

What Is Koridashi? Origins and Philosophy

Koridashi (氷出し) translates to "ice brew" in Japanese, and that’s exactly what it is. This method involves placing tea leaves beneath a few ice cubes and letting them melt slowly to extract the flavor. Rooted in Japanese tea culture, Koridashi is often used to brew high-quality green teas like Gyokuro or Sencha.

These teas are known for their delicate, umami-rich profiles that shine best when brewed at low temperatures. While the process certainly results in new and exciting flavors in a given cup of tea, it’s also seen as a meditative, slow ritual that turns tea-making into an exercise in mindfulness.

Koridashi vs. Cold Brew: What’s the Difference?

At first glance, Koridashi may sound like cold brew, but the two methods are actually quite different.

Cold brew typically involves steeping tea leaves in cold water for several hours. Koridashi, on the other hand, skips the water entirely. Instead, the leaves rest beneath ice cubes, and it’s the melting ice that gently coaxes out the flavor. This results in a more concentrated, layered infusion with a naturally sweet, umami-rich taste.

Think of it as the difference between chilling a drink and letting it reveal itself at its own pace.

Why It Works: Umami Without Bitterness

The science behind Koridashi is simple but powerful. Brewing tea at very low temperatures prevents the extraction of tannins, which are responsible for bitterness and astringency. What you get instead is a smooth, mellow cup that highlights the tea’s natural sweetness and savory umami notes.

This method is especially effective with shade-grown Japanese teas like Gyokuro, which are rich in amino acids like L-theanine. Using this method, you get a brew that feels soft on the palate, with a lingering richness that’s hard to achieve with hot water.
Bonus: it’s also lower in caffeine, making it a great option for all-day sipping.

Step-by-Step: How to Brew Tea with Koridashi

Ready to give Koridashi a try? Here’s how to do it:

What You’ll Need:
- Loose leaf tea (preferably high-quality Japanese green tea)
- A small teapot, glass cup, or glass pitcher
- Ice cubes

Brewing Instructions:
1. Add about 5 grams (roughly 1–2 teaspoons) of loose leaf tea to your brewing vessel.
2. Place 6–8 ice cubes directly on top of the leaves.
3. Let the ice melt slowly at room temperature or in the fridge. This can take anywhere from 30 minutes to 2 hours, depending on conditions.
4. Once melted, pour and enjoy. The flavors will be nuanced and refreshing.

Pro Tips:
- Use large, clear ice cubes for a slower melt and better visual effect.
- Avoid using metal containers, as they may alter flavor.
- Serve in a chilled glass for the full experience.

Best Teas for Koridashi Brewing

Koridashi is a match made in heaven for delicate Japanese greens. Try it with Gyokuro or Sencha Premier.

Want to get creative? Experiment with:
- White teas for a floral, honeyed brew.
- Light oolongs for a silky, complex twist.
- Herbal blends like hibiscus or chamomile for an iced infusion without caffeine.

The Joy of Slowing Down

There’s something deeply calming about Koridashi. Watching the ice melt gives you a second to slow down, take a breath, and be present. This isn’t a rushed cup on the go, after all. It’s a practice in patience, and a reminder that flavor doesn’t need to be forced.

Serving Ideas and Pairings

Want to take your ice brew to the next level? Try these serving ideas:

- Serve in a chilled wine or cocktail glass with a twist of citrus peel.
- Add a sprig of mint or a slice of cucumber for spa-day vibes.
- Turn it into a tea spritzer with a splash of sparkling water.

For pairings, think light and fresh: fruit, rice crackers, sushi, or a crisp salad with sesame dressing.

A Cool New Ritual to Try This Summer

Koridashi is a slow, refreshing, and deliciously suited way to enjoy the season’s warm days and long evenings. This method is a fun and flavorful way for anyone to deepen their tea journey.

Pick your favorite loose leaf tea, grab some ice, and see if you can discover a different side to the same teas you were brewing hot just yesterday.