Different grind sizes do not seem to make material difference in coffee taste - Page 2

Coffee preparation techniques besides espresso like pourover.
jpender
Posts: 3863
Joined: 11 years ago

#11: Post by jpender »

mikelipino wrote:Note the scale on the supplemental figures from the Nature paper. Per the Nature paper cited above, p. 9, paragraph 1 (emphasis mine):

"The coffee grind particle size did have a very minor effect on TDS. For the brews at Rbrew = 15 at 99 °C, both the equilibrium TDS and E are negatively correlated with the median of grind particle size with a correlation coefficient of −0.978 and −0.992 (solid lines in Supplementary Fig. S4), that is, coffee brewed with finer coffee grounds resulted in slightly higher TDS and E. The TDS was 1.36 ± 0.09% over a huge range of grind particle sizes, from a median particle size of 579 μm to 1311 μm (cf. Supplementary Fig. S1), but these small TDS differences are difficult to discern compared to the major effect of Rbrew over the entire range of brew ratios tested.

TLDR, grind size has a minor effect on TDS, but it's largely overshadowed by brew ratio.

Yes, of course the brew ratio is the primary determinant of the concentration of the beverage. That doesn't take away from the fact that, when you hold everything else constant, large changes in grind do have a significant impact on both concentration and extraction.

Here's a simple experiment that was done ten years ago with an Aeropress (by @Netphilosopher). He varied the grind from pourover to press pot, while keeping everything else constant. It looks very much like that figure in the supplement for the journal article.




What we don't know is how these different coffees tasted.

Acavia (original poster)
Posts: 689
Joined: 4 years ago

#12: Post by Acavia (original poster) »

I made two brews today, one in Aeropress and one in V60. The two brews were almost indistinguishable. Aeropress 4.5 Ditting-Sweet grind, 18.18:1 11.3g Hoffmann method. V60 12g 18:1 5 grind setting. Both 209F water. I used two filters in Aeropress. Cafec medium filter in V60. The V60 was not really even cleaner tasting - it was pretty much the same coffee as I alternated drinking both.

rmongiovi
Posts: 460
Joined: 17 years ago

#13: Post by rmongiovi »

I do strictly immersion. Right now with a Clever. I use a Kafatek MAX flat burr grinder. Very small adjustments in grind size make a very big difference in the taste. I don't measure TDS so I can't speak for that, but for me immersion definitely doesn't make up for getting the grind size right.

Bitter to the left of me, sour to the right, stuck in the middle with brew.

User avatar
LBIespresso
Supporter ❤
Posts: 1226
Joined: 7 years ago

#14: Post by LBIespresso »

jpender wrote: Yes, of course the brew ratio is the primary determinant of the concentration of the beverage. That doesn't take away from the fact that, when you hold everything else constant, large changes in grind do have a significant impact on both concentration and extraction.
So doesn't this combined with the fact that large changes in brew temp will have a significant impact as well tell us that we should be changing brew ratio until we get the best we can before trying to adjust grind size or brew temp?

I have recently become obsessed with improving my PO so I appreciate input from those with more experience.
LMWDP #580

jpender
Posts: 3863
Joined: 11 years ago

#15: Post by jpender »

LBIespresso wrote:So doesn't this combined with the fact that large changes in brew temp will have a significant impact as well tell us that we should be changing brew ratio until we get the best we can before trying to adjust grind size or brew temp?
Brew ratio primarily affects the strength of the coffee, not the extraction, in immersion brews.

For sure temperature can have a significant effect. The brewing method I mentioned earlier where I got near 25% extraction resulted in drinkable coffee when I used 80°C water. When I used the exact same method but with 94°C water the coffee was very bitter. However, with 94°C water and a much larger grind the coffee once again tasted good.

Brew ratio isn't completely decoupled from extraction. Higher coffee/water ratios pull the slurry temperature down which can affect the balance. And a lower temperature, as well as higher concentration, slows the extraction. But to first approximation the brew ratio is a way to select the strength.

LBIespresso wrote:I have recently become obsessed with improving my PO so I appreciate input from those with more experience.
That's really a different subject than immersion brewing.

Ocran
Posts: 18
Joined: 2 years ago

#16: Post by Ocran »

When we moved from a cheap burr grinder to the super jolly, we noticed an incredible improvement in taste with our French Press, not to mention the significant reduction in fines.

But I'd agree, now that we have a good grinder, I don't taste a noticeable difference in the cup - it is very much noise level compared to the different roasts that we try.

I contribute the initial improvement with the super jolly to be the the precision of the grind size.

jpender
Posts: 3863
Joined: 11 years ago

#17: Post by jpender »

Ocran wrote:But I'd agree, now that we have a good grinder, I don't taste a noticeable difference in the cup - it is very much noise level compared to the different roasts that we try.

I contribute the initial improvement with the super jolly to be the the precision of the grind size.
If grind setting changes result in differences that are lost in the noise then how could precision of grind size possibly matter? You should be able to use a blade grinder and get essentially the same result as coarse ground coffee or Turkish or a mad combination-- if grind size doesn't make much difference.

Ocran
Posts: 18
Joined: 2 years ago

#18: Post by Ocran »

Precision of the grind translates to grind uniformity, which is not possible in a blade grinder (or the cheap conical Burr grinder we were coming from). In other words, the fines from a blad grinder "mud up" the French press and completely change the experience.

Now that we have the super jolly, I've played with different grind settings, but nothing adds up to the night and day difference of the uniform grind from the SJ.

Perhaps "in the noise" was a strong statement.

ohwhen
Posts: 65
Joined: 3 years ago

#19: Post by ohwhen »

Acavia wrote: Can you get that high of extractions with Aeropress? Doing such a fine grind, off boil water and 18.18:1 ratio, I assume my first brew would have been near the top for Aeropress.
If you're interested in high extraction Aeropress brews, I would recommend checking out Jonathon Gagne's 10 minute steep recipe and accompanying blog post. It took me a few tried to dial in correctly, I definitely noticed a difference with minor grind size adjustments.

https://coffeeadastra.com/2021/09/07/re ... aeropress/

User avatar
Phobic
Posts: 82
Joined: 8 years ago

#20: Post by Phobic »

Slightly old thread but this is something I've been thinking about and researching for the last few days, thought this was the best place to add my thoughts and questions.

I love immersion generally and have always ground pretty fine on the basis that it's hard to over extract with immersion, I also generally do long steeps - e.g. in a softbrew I'll happily do a 45 min steep

Matt Perger makes some interesting points about grind size v extraction http://www.youtube.com/watch?v=2lPGf1gM9nA

as a result my current thinking is
- 100 micron penetration max is achieved, 200 micron diameter
- Over extracting in immersion is hard to do - Matt's lecture suggests you need to boil the grinds with water in a pan!
- My immersion goal is to hit extraction equilibrium as quickly as possible
- immersion time allows the water to cool which de-risks over extraction

with this in mind I just tried a 10 min inverted Aeropress at Espresso grind size in an EK43, light roast, 99c input temp, all the water in quickly and stir - the result was very tasty though a little drying on the palette overall. 18g > 250g 1.76% TDS and 25.89% extraction (pretty impressive).

The aeropress & filter had no issue dealing with this grind size, still and easy plunge and clear cup at the end.

purely anecdotal observation but taste changed through the drinking time as temps dropped, on my 1st sip I thought it was bitter and over extracted, this disappeared by the 2nd sip, through the middle of the cup there was dryness aftertaste, but this disappeared towards the end as things cooled - I plan to try this again later and let the cup cool more before I start drinking.

I've also been reading a lot about fines for brew, especially distribution and the effects of agitation.

I plan to repeat this again and see how far I can reduce the time but will give the Ad Astra method a try without a Prismo https://coffeeadastra.com/2021/09/07/re ... eropress/

really interested in hearing about anyone else who's given very fine grind immersion a try.

has anyone got any thoughts on grind size v over extraction potential in immersion v time to hit equilibrium v temp?