Tetsu Kasuya's 4:6 Method

Tetsu Kasuya’s 4:6 Method changed the landscape of pour-over brewing when it won the 2016 World Brewers Cup competition in Dublin. The technique introduced a radical concept: by dividing the total water volume into a 40% first phase and a 60% second phase, a brewer can independently control the balance of sweetness and acidity (phase one) and the overall strength (phase two) of the finished cup.

What made the 4:6 Method revolutionary was not just its competition success, but its conceptual clarity. Previous V60 techniques focused primarily on mechanical execution, asking the brewer to replicate specific pouring patterns and timing. Kasuya’s method instead gave brewers a framework for understanding what each pour actually does to the cup, turning recipe adjustment from trial-and-error into a deliberate, logical process.

The Core Concept

The 4:6 Method divides your total water into two functional phases. The first 40% of the water controls the flavor balance between sweetness and acidity. The remaining 60% controls the strength, or concentration, of the brew.

For the standard recipe of 20g of coffee to 300g of water (1:15 ratio), this means:

• First phase (40%): 120g of water, controlling sweetness vs. acidity
• Second phase (60%): 180g of water, controlling strength

Each phase is further divided into individual pours, and the way you distribute water within each phase determines the final cup profile. This modular structure is what gives the method its remarkable versatility.

Why a Coarse Grind

One of the most immediately distinctive aspects of the 4:6 Method is its use of a coarser grind than most V60 recipes. Where the typical V60 recipe calls for medium-fine (like table salt), Kasuya recommends a coarse grind closer to what you might use for French press.

This grind choice is deliberate and essential to the method’s mechanics. The coarser grind creates faster drawdown between pours, which is critical because the method relies on multiple discrete pours with waiting periods between them. If the grind were finer, the bed would retain water between pours, blurring the distinction between phases and undermining the brewer’s ability to control each variable independently.

The coarser grind also means that each individual pour extracts less aggressively, which gives the multi-pour structure time to build flavor incrementally. The total extraction is achieved through the cumulative effect of all pours rather than through a single, highly efficient pass through a fine bed.

Phase One: Controlling Flavor Balance (First 40%)

The first 120g of water is divided into two pours of 60g each. How you distribute these two pours determines the sweetness-acidity balance of your cup.

For a sweeter cup: Make the first pour larger and the second pour smaller. For example, 70g then 50g. The larger initial pour extracts more of the sweet and acidic compounds early, and the smaller follow-up allows the sweet notes to dominate.

For a more acidic (brighter) cup: Make the first pour smaller and the second pour larger. For example, 50g then 70g. The smaller initial pour extracts less sweetness up front, allowing the naturally acidic compounds to remain more prominent in the finished cup.

For a balanced cup: Keep both pours equal at 60g each. This is the recommended starting point for any new coffee.

Between each pour in phase one, wait for the water to draw down until the surface of the coffee bed is visible before adding the next pour. This waiting period is essential. It ensures that each pour interacts with the coffee bed independently rather than simply adding volume to a pool of standing water.

Phase Two: Controlling Strength (Remaining 60%)

The second phase uses the remaining 180g of water and is divided into three equal pours of 60g each. The number of pours in this phase determines the strength of the final cup.

For a stronger cup: Use fewer, larger pours. Instead of three pours of 60g, try two pours of 90g. Fewer pours mean more contact time per pour and more extraction.

For a lighter cup: Use more, smaller pours. Instead of three pours of 60g, try four pours of 45g, or even six pours of 30g. More pours with less volume each extract less aggressively, producing a lighter-bodied cup.

The standard three-pour approach at 60g each produces a medium-strength cup that works well as a baseline for most coffees.

As with phase one, wait for the water to draw down between each pour. The bed should be visible before you add the next addition.

Step-by-Step Standard Recipe

This is the baseline recipe: balanced flavor, medium strength.

Equipment

• Hario V60 02
• V60 paper filter
• Gooseneck kettle at 93°C (199°F)
• Scale and timer
• 20g coffee, ground coarse
• 300g water total

Execution

Pour 1 (0:00): Pour 60g of water. Aim for the center of the bed, pouring in small circles. The coarse grind will mean less dramatic blooming than you may be accustomed to, but CO2 release is still occurring.

Wait: Allow the water to draw down until the coffee bed surface is visible. This typically takes 30-45 seconds.

Pour 2 (~0:45): Pour another 60g of water, bringing the total to 120g. Again, pour into the center in gentle circles.

Wait: Allow full drawdown. You have now completed phase one with 120g of water (40% of total).

Pour 3 (~1:30): Pour 60g of water, bringing the total to 180g. This begins phase two.

Wait: Allow full drawdown.

Pour 4 (~2:15): Pour 60g, total now 240g.

Wait: Allow full drawdown.

Pour 5 (~3:00): Pour the final 60g, total now 300g.

Drawdown: Allow the remaining water to pass through the bed. Total brew time should be approximately 3:30 to 4:00.

The Adjustment Matrix

The power of the 4:6 Method lies in its systematic adjustability. Here is a summary of how to modify each parameter:

This matrix gives the brewer six distinct cup profiles using the same coffee and the same total water volume. The ability to systematically dial in a coffee’s presentation without changing grind size or ratio is what makes the method so compelling for both casual brewers and competition professionals.

Why the Method Works

The 4:6 Method exploits a fundamental principle of extraction chemistry: different flavor compounds dissolve at different rates. Acids and light fruity compounds extract first, followed by sugars and sweetness, and finally heavier, more bitter compounds.

By controlling how much water contacts the coffee in the early stages (phase one), the brewer determines how much of the early-extracting acidic and sweet compounds end up in the cup relative to each other. By controlling the number and size of pours in the later stages (phase two), the brewer determines how much total extraction occurs, which directly maps to perceived strength.

The coarse grind is essential to this separation. A finer grind would extract everything faster, collapsing the distinction between phases and limiting the brewer’s ability to adjust one variable without affecting the other. The coarse grind slows overall extraction enough that the sequential pour structure can do its work.

Adapting for Different Coffees

Light roasts: Light roasts benefit from slightly hotter water (96°C / 205°F or even boiling) and may need a slightly finer grind than the standard coarse setting. The 4:6 structure helps manage the brightness that light roasts naturally exhibit. Start with a balanced phase one and adjust toward sweetness if the cup is too sharp.

Dark roasts: Dark roasts are more soluble and extract faster. Use cooler water (88-90°C / 190-194°F) and consider using more pours in phase two (four or five smaller pours) to avoid over-extraction and bitterness.

Natural processed coffees: These tend to be fruit-forward and sweet. The 4:6 Method is excellent for naturals because phase one allows you to emphasize or tame the fruit character. If the coffee is overwhelmingly fruity, shift phase one toward a brighter profile (smaller first pour) to add structure.

Washed coffees: Washed coffees are typically cleaner and more acidic. Shifting phase one toward sweetness (larger first pour) often brings out the best in high-quality washed lots by tempering the acidity with sweetness.

Scaling the Recipe

The 4:6 Method scales well. The key is maintaining the 1:15 ratio and the 40/60 water split.

For a smaller cup: 15g coffee, 225g water. Phase one: 90g (two pours of 45g). Phase two: 135g (three pours of 45g).

For a larger cup: 25g coffee, 375g water. Phase one: 150g (two pours of 75g). Phase two: 225g (three pours of 75g).

The coarse grind should remain consistent regardless of batch size. Total brew time will increase slightly with larger doses, but the drawdown timing between pours should remain similar.

Troubleshooting

Sour or underdeveloped flavor: The coarse grind may be limiting extraction. Try grinding slightly finer, but not so fine that drawdown between pours stalls. Alternatively, increase water temperature by 2-3 degrees.

Bitter or astringent flavor: The grind may be too fine for this method, causing over-extraction during the longer contact time of multiple pours. Coarsen the grind. You can also reduce water temperature or add an additional pour to phase two (smaller individual volumes, less extraction per pour).

Watery or thin body: Try reducing the number of pours in phase two (two larger pours instead of three standard ones). This concentrates extraction and increases perceived body.

Drawdown between pours takes too long: The grind is too fine. Coarsen until you see clear drawdown within 30-45 seconds of each pour.

All pours drain instantly: The grind is too coarse. Go finer until each pour takes at least 20-30 seconds to visibly draw down.

Competition Context

Kasuya’s victory at the 2016 World Brewers Cup was significant not just for the trophy, but for what it represented. The competition had traditionally favored highly technical, precision-driven techniques. Kasuya’s method, with its coarse grind and conceptual simplicity, demonstrated that an elegant framework for understanding extraction could outperform brute-force technical execution.

The method has since been adopted and adapted by competitors around the world. Its influence extends beyond the V60: the principle of dividing water into functional phases has been applied to Chemex, Kalita Wave, and other pour-over devices with various modifications. The 4:6 framework has become a standard reference point in brewing education, giving students a vocabulary for discussing how water distribution affects cup quality.