The science behind Kasuya 4:6 method? - Page 2

Coffee preparation techniques besides espresso like pourover.
vit

#11: Post by vit »

As about channeling (which was most likely my problem before trying this method - especially with James' method where there is lots of water above the coffee), small pours seem to be more forgiving

As about the temperature, on last brew (with 4:6) I screwed with it, first pour was with kettle temperature 91 and last with about 85 (actually similar to his recommendation, although I was targeting to start at 95-96), but result was surprisingly pleasant ...

But as I said, I need more attempts to draw some more solid conclusions about this and other methods ...

A thing to note, Tatsu is using modified V60 version with ribs smoothed at the bottom to decrease the flow. Tryng to simulate that, I used Melitta dripper on last 3 attempts (instead of V60 used previously), which has lower flow than V60, and coarser grind (490 on Kinu)

Jonk

#12: Post by Jonk »

ojt wrote: I have found that a bloom + 2 pours is the sweet-spot-method for most coffees I enjoy
I agree that this is a pretty foolproof method that works well. I like to maximize agitation and swirl after each pour, just making sure that the water level never drops below the grounds and only add more pours if necessary when brewing larger batches.

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vit

#13: Post by vit »

So, here are some measurements

As I already mentioned, I'm a beginner in pourover, tried several methods found on internet and some combinations of them and recently tried 4:6 method. ATM it's not important that so far I had more luck with 4:6 than with other methods, as my pourover skills are obviously in need of improvement, but these measurements may give some more info or inspire someone else to do more measurements, as there are not much data of this kind available, so there is lots of room for pseudoscience

On the graphs, green line is the quantity of water poured in (right scale, in g), brown line is slurry temperature about 5-6mm below the surface of the coffee bed, measured with k-probe (left scale, in °C) and blue line is the water temperature in the kettle measured with kitchen thermometer in the kettle (°C)

For pouring, I used relatively small/cheap gooseneck kettle holding about 4 dl of water which I reheated on the stove between the pours

First graph is 4:6 method, which I hopefully did by the book. I made first pour slightly shorter than the second. Coffee bed surface dried up between all pours. I used

- 13.6 g Ethiopian medium roast, ground on Kinu @ 4.9.0
- plastic Melitta compatible 1 cup dripper (made in China)
- original Melitta 1x2 filter (made in Germany)



Second graph is my attempt of James Hoffmann's method, although main pour was more like 80:20 than 60:40 as I tried following his recommendation to fill the water close to the rim relatively fast to increase the thermal mass, which was important due to smaller than usual quantity of the coffee and water. Not sure what should be the total length of the brew either. I used

- 13.6 g Ethiopian medium roast, ground on Kinu @ 4.0.0
- plastic V60 compatible 1 cup dripper (made in China)
- noname V60 filter (made in China)



Both measurements are not entirely comparable, as somewhat different dripper was used. I used Melitta for 4:6 to decrease the flow; Tatsu is otherwise using his own version of V60 that also has reduced flow. Shape of the coffee in Melitta is a bit different, which probably had some impact on the measurements, although I believe it wasn't big

Unexpectedly, average temperature near the top of the coffee bed with 4:6 wasn't much lower than with Hoffman's method, despite pulse pouring and drying of the surface between the pours and also 2-3°C lower kettle temperature used. It looks like only surface of the coffee bed is actually cooler than with Hoffmann's method, which maybe isn't a bad thing, because it's most extracted by the flow anyway, so maybe this helps to achieve a more even extraction. So it looks like lots of water with Hoffman's method doesn't help as much as it should - or at least it didn't help in my case ... it's probably because larger water surface closer to boiling point cools down quite fast due to intensive evaporation. Covering the dripper with something (as some suggest) would surely help to retain higher brewing temperature (if needed)

Jeff
Team HB

#14: Post by Jeff »

Slightly OT:

One thing that I recall from JH's video is "ultimate" is in terms of repeatedly good results without a lot of expertise, fiddling, or fancy gear. The Kalita technique Nick Cho taught us a decade or so ago, falls into the same category. "It just works" across a wide range of grinders, beans, and skill levels.

zefkir

#15: Post by zefkir »

The issue behind the 4:6 method has never been the pulse pour pattern, it's the nonsensical pseudo-scientific explanation. Some people have attempted to rationalize it but I think the explanation was created to satisfy the requirements of a barista competition where every move you make has to have a fancy reason.

Personally, I don't like too many pulses in a pour because it creates extraneous agitation that creates clogging and therefore forces you to grind coarser (unless you have an outstanding grinder), leaving perfectly tasty compounds in the coffee grounds. A bloom and two pours have treated me well, I might even go to three if I have a particularly fines-free bean.

5cylinders

#16: Post by 5cylinders »

The 4:6 methods is a decent one, but, not because of what the author claimed. It's just a member of pulse pouring family, with a share of the merit.
The key claim to make this method stand out, is that we can control the balance between sweetness and acidity by adjusting the amount of 1st and 2nd pour.
No, we can't. Coffee compounds dissolution is not as comforting as "acid first, then sugar, bitter stuff last" fantasy. One example: tasting the blooming liquid, it can be sour, sweet, dominantly bitter, or blank, dependent on water temperatures and bloom ratios.
As for sweetness, I'd like to draw some support from a research paper from UC Davis centre ( https://onlinelibrary.wiley.com/doi/abs ... jsfa.10323 ). "The perceived sweetness had nothing to do with the sugars present in the brew", because "the total concentration of all the sugars present in each (time) fraction is well below the threshold of human perception", and, "the earlier fractions were systematically more bitter and more sour than later", "sweetness systematically increased with later fractions (peaking at 3:30)". One possible explanation "is that the human brain associates certain flavor attributes with things that are sweet, so the mind is 'tricked' into thinking the presence of those attributes means there must be sweetness", "perceptible sweetness in coffee is a consequence of masking effects and/or the presence of sweet-associated aromas and flavors. "
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vit

#17: Post by vit »

Leaving the pseudoscience aside, did anyone actually tried experimenting with ratio between 1st and 2nd pour ? Number of my samples is currently too low to draw any meaningful conclusions

I suppose Tatsu experimented with it first and then some pseudoscience was made around it by him and others, at least that's what I would do, but maybe I'm wrong

I see that general discussion about continuous vs pulse pour methods is much wider and everybody seems to have own preferences depending on brewer, quantity, coffee used, roast, grinder, kettle etc, already discussed on this forum and elsewhere so it is probably OT here. But interestingly, most seem to prefer having water level low above the grounds - directly opposite to James' method ...