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Understanding Tetsu Kasuya’s 4:6 Pour Over Method

Tetsu Kasuya 4-6 Method

The 4:6 method is a pour over recipe invented by Tetsu Kasuya. It started to get buzz when Tetsu used it to win the 2016 World Brewers Championship. 

The basic concept of this method is to be able to control the flavor of your coffee by adjusting your pouring. The first 40% controls the balance of flavors and the remaining 60% controls the strength of the brew. Hence, the name, 4:6. 

While there is a lot of information already on the basics of the method, we want to take a deeper dive as to how this recipe works – so you can apply these concepts to your brews.

Read on to learn more about this competition-winning recipe!

Recipe Guide

  • Dose (g): 20
  • Total amount (ml): 300
  • Brewing device: Hario V60
  • Ratio: 1:15
  • Grind size: coarse
  • Water temperature: 92°C / 198°F (distilled water)
  • Pouring pattern (ml): 60 – 60– 60 – 60 – 60
  • Pouring intervals (minutes to seconds): 45 seconds in between pours
  • Total time (minutes to seconds): Between 3:15 to 3:30

Pouring pattern

In its most basic form, the 4:6 recipe is really straightforward way of making pour overs. Pour 60ml of water every 45 seconds. To further control the flavor of your coffee, you can adjust your pouring for the initial 40% of the brew, and the remaining 60% adjusts the strength. Let’s unpack what that means.

40% of the brew controls flavor balance

According to Tetsu, the first two pours adjust the balance of sweetness and acidity. If you want a sweeter cup, pour less at the start and more on the second pour. Tetsu recommends 50ml and 70ml here. 

If you want a brighter cup, pour more for the first pour and less at the second. Tetsu recommends the reverse by first starting with 70ml then 50ml. 

To understand what’s happening here, you’ll need to know a bit about how coffee extracts. In a nutshell, different flavor aspects in the coffee extract at different stages of the brew. And some ways you can extract more of these flavors is by pouring more water, increasing the number of pours, or by increasing the total brew time.

TimeFlavor aspect
0:00 – 0:30 / the bloomSharpest and unbalanced acidity
0:30 – 1:00 Calm to gentle acidities
1:00 – 1:30Sweetness
1:30 – 2:00Body, texture
2:00 – 2:30Slight sweetness and more bod
3:00 – 3:30Slightly bitter flavors
To keep this example simple, we’re using 30 second intervals to separate each flavor aspect. Just note this does vary depending on the coffee being used

From this chart, you can already get an idea of why Tetsu says doing a 70ml pour for the bloom brings in more acidity, while a 50ml bloom brings more sweetness. 

We previously did a test on how different bloom amounts affect a coffee’s flavor. And it lines up perfectly with what Tetsu says about acidity. Anything more than 3x the weight of the dose will bring in more acidity. Read more about our test results here.

Acidity gets extracted at the very start of the brew. So pouring more water for the bloom will extract more acidity. On the flip side, a smaller pour on the bloom with a heavier second pour gets more sweetness because that’s the stage where sweetness extracts!

60% of the brew controls the strength of the coffee

From the third pour onwards, you’ll notice your coffee will start to take longer and longer to drain. That’s not mere coincidence. 

That’s because the most soluble compounds of the coffee were already extracted in the first two pours. Since the remaining bits are not as easy to extract, your water will need a bit more time to go through the coffee. 

According to Tetsu, to decrease the strength of your coffee, do only 2 pours of 90ml every 45 seconds instead of 3 pours of 60ml. And if you want a stronger brew, do 2 pours of 60ml and the last 2 pours of 30ml. 

What’s happening here is that with more pours, you’re both agitating the coffee more and extending the brew time. We learned earlier that agitating more and a longer brew time will mean more extraction. This still applies. 

With a heavier pour, while you supposedly get the extraction from pouring more water, it doesn’t extract as much compared to doing more pours and prolonging the brew time. 

Notice also that the flavor aspects extracted in the later parts of the brew mostly deal with what we call ‘body’. This refers to how viscous the coffee is. 

Another way to think about it is how heavy the coffee feels in your mouth. It follows that a lighter brew tastes weaker than a heavier one.  

Grind size

For this recipe to work, you’ll need to grind quite coarse. In fact, most recipes with many pours involved will recommend grinding coare. 

Again, that’s because having more pours agitates the grounds more and prolongs the brew time. If you were to do many pours on a finer grind size, the coffee might take too long to drain. And if you’re not careful, you might over-extract the coffee.

What we like about the 4:6 method

Beginner-friendly

Many pour over enthusiasts started with the 4:6 method. Among the pour over methods, it really is as simple as it gets. 

The more you divide your pours, the easier it is to manage the technique compared to doing just one long pour. And since this recipe has a lot of pours, it’s quite forgiving. 

What’s also cool about this method is that it can make learning to use a Hario V60 easy – especially when this is infamously difficult to master among the pour over devices. 

Repeatable/consistent

Apart from being simple, another plus for this technique is that it’s easy to get consistent results with it. 

Since pour over brews are completely done by hand, they naturally are prone to some inconsistencies. But this method balances that out with how forgiving it is. 

Easy to adjust

If you’re switching from one coffee to another and it’s not tasting the way you want it to, this method gives you a good guide on what to adjust with your brew and easily troubleshoot. 

As long as grind size isn’t the issue, you can easily adjust the number of pours you have at the end if your brew tastes weak. Same with the acidity, just pour less at the start if your cup is too bright. 

You’ll know grind size is the problem when the coffee drains too quickly or too slowly, even if you’ve adjusted your pouring. 

If it’s too quick, your brew will taste watery (sometimes even sour) and you’ll have to go a bit finer. If it’s too slow, your brew will taste bitter (and sometimes astringent) so you’ll have to go coarser. 

What we don’t like about the 4:6 method

Low-extraction brew

Brewing Variables that Affect Extraction

One very important aspect about the 4:6 method nobody talks about is that Tetsu uses distilled water. Meaning, his water has no mineral content (0 TDS). Most modern cafés will have the Total Dissolved Solids (TDS) reading for their water around 70 to 100 parts per million (PPM) .  

We’ve talked about how pouring more water, dividing your pours, and prolonging the brew time can increase extraction. Using a finer grind size and a higher TDS water are other ways to increase extraction.

Since the 4:6 method uses distilled water and a coarse grind size, the brew overall yields a low extraction. That doesn’t automatically make this a bad recipe. But it is limiting. 

This roast particularly worked well for Tetsu because the Japanese-style roasts are quite dark. So he wouldn’t want to extract as much since bitter flavors are easy to extract with dark roasts. 

If you were to apply this recipe on very light or Nordic-style roasts, it wouldn’t work. Those types of roasts are so light and packed with flavor that a coarse grind wouldn’t be enough to get much out of them. You’ll just end up with a weak and sour brew that way. 

Long brew time

Most brew recipes now call for a total brew time of between 2 and a half minutes to 3 minutes. While 30 seconds to a minute might not be a lot, it’s inefficient if you’re serving at a bar. 

The long wait time in between pours also makes the cup taste less “full” because the temperature in the slurry is not constant. 

Final thoughts

The 4:6 offers a crisp brew with a lot of clarity. It is a great brewing method to play around with, especially if you want to understand how flavors get extracted. You can also get a lot of consistency with this method because of how forgiving it is, regardless of the brewer you’ll use.

Like anything though, the 4:6 is not perfect. It is slow and won’t work as well with very light roasts. 

While this recipe won a world competition, it’s important to remember it’s just one way to brew coffee. But it isn’t the only way. 

What works for one coffee might not work so well for another. That’s why everyone competing in the World Brewers Championship has their unique recipes – to best suit the coffee they’re using. 

Likewise, we recommend you do the same. Learn what you can about different recipes and see which one suits your coffee the best. 

Frequently asked questions

Can this method be used with other brewers (Kalita, Chemex, etc.)?

Yes, it can. Just keep in mind that when using other brewers, this recipe won’t behave exactly the same way as with a V60. The V60 naturally has a fast flow rate compared to most brewers. So expect your brews to take a bit longer to drain. 

Can you use finer grind sizes for this method?

Yes. But you’ll have to shorten your time in between pours since finer grind settings will naturally take longer to drain. So to not prolong your brew for too long, you’ll need to shorten each pour. You’ll also need to do fewer pours for the same reasons. 


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