You need to try barista Tetsu Kasuya's 4:6 technique! It's a fantastic method for brewing coffee with a V60.

Introduction

You might already be familiar with the V60 brewing method, but if you think it's limited to basic coffee extraction, you're missing out. There are fantastic techniques that, when applied correctly, can significantly enhance the flavor of your brew. That’s why you need to experience the 4:6 method by barista Tetsu Kasuya!

First, remember that the V60 method is a popular and beloved way to brew filtered coffee among coffee lovers. The unique spiral ridges on the inside of the V60 help coffee grounds expand during the brewing process, which gives a distinctive taste compared to a standard coffee filter. Now, when you combine the V60 with Tetsu Kasuya’s 4:6 technique, it gets even better.

The sensory result of brewing coffee with the Tetsu technique can highlight the bean’s sweetness and acidity, but it must be done correctly. Details like grind size, pre-infusion time, and other factors are essential to getting the best out of the 4:6 technique for V60. Want to learn how to brew using the Tetsu method? Keep reading — we’ll teach you step by step!

But Who is Tetsu Kasuya?

Tetsu Kasuya is a renowned Asian barista in the world of specialty coffee. In 2016, he won the World Brewers Cup with his now-famous 4:6 V60 technique, which helped him secure victory in the competition.

Today, Tetsu Kasuya works globally, including in Japan, as a coach, consultant, and product developer. He also serves as a judge in coffee competitions, helping to train and inspire future baristas. Additionally, in honor of his achievement, the company Hario teamed up with Tetsu to create the “Kasuya Model Series,” a line of black coffee equipment specifically designed to make replicating the 4:6 method easier.

What is the Tetsu Kasuya or 4:6 Technique for V60?

According to Tetsu, the theory behind the 4:6 method involves pouring water over the grounds in controlled amounts and stages. The first 40% of water is poured in two stages, which determines the balance between sweetness and acidity. The remaining 60% of water, divided into three stages, sets the intensity of the coffee. Don’t worry, we’re giving you an overview—you’ll learn the step-by-step process shortly.

Experts say the first moments of coffee extraction are crucial to achieving a great cup. Espresso machine manufacturers already understand this, using precise pressure and time controls during the initial extraction stages. Tetsu’s 4:6 Method follows this same principle.

The Basic 4:6 Method

The process is simple. Kasuya’s technique divides the pour into 5 stages, with 60ml of water per pour. Each pour should be spaced out by 45 seconds, so after completing all five pours, you’ll have 3 minutes and 30 seconds in total extraction time.

The two phases of Tetsu’s technique can be adjusted, but the total extraction time of 3 minutes and 30 seconds should remain consistent. These adjustments can change the sensory profile of your coffee, emphasizing sweetness, acidity, or intensity. Here's how!

How to Increase Coffee Sweetness

To highlight the sweetness, focus on the initial pours. By reducing the amount of water in the first stage, you can enhance sweetness.

For example, you might use 50ml of water in the first pour (which takes about 38 seconds) and 70ml in the second stage, resulting in 120ml of water after 1 minute and 30 seconds, the same as the basic method.

How to Increase Coffee Acidity

Conversely, if you want to increase acidity, reverse the water amounts—use 70ml in the first pour and 50ml in the second. Here's an illustration for clarity:

How to Make Coffee More Intense

To increase the intensity of your brew, Tetsu suggests adding an extra water pour in the second part of the extraction. Instead of 3 stages for the last 60% of water, divide it into 4 pours of 45ml each, with 30 seconds per pour.

For a less intense result, you can reduce the number of pours while increasing the volume of each one to 90ml, with 1 minute for each pour.

Remember, the full extraction time should still be 3 minutes and 30 seconds with 300ml of water. After that, just serve and enjoy!

What You Need to Apply the Tetsu Kasuya Technique

To use the 4:6 method, you’ll need the following tools:

• Gooseneck Kettle: Ensures precise control over water flow during each pour.
• Scale and Timer: Some scales come with built-in timers, but if not, use a separate timer.
• V60 Dripper (No. 2): The size Tetsu used for his original 4:6 recipe.
• Grinder: You’ll need to adjust the grind size to suit the recipe timing. For the 4:6 method, use a coarser grind, similar to the texture of cornmeal.
• High-Quality Coffee: No method, not even Tetsu's, will work wonders without good coffee beans! Choose specialty-grade beans for the best results.

For the best results, follow Tetsu’s steps precisely, including the right amount of coffee and water:

• 20g of coffee (with the coarse grind mentioned earlier)
• 300ml of water

Sensory Analysis

We tested the Tetsu Kasuya method using a Yellow Bourbon coffee, and the results were impressive. The brew had elevated sweetness and acidity, delivering a delightful and balanced cup.

In conclusion, we challenge you to try the V60 method in a new way. Brew it at home or ask your local barista to give it a go!