
Effect of bean origin and temperature on grinding roasted coffee (2016) - WMCRUN
https://www.nature.com/articles/srep24483
======
jedimastert
For those interested in this sort of thing, James Hoffmann[0] has some really
well presented videos about coffee, the making and iterating on, from the
perspective of someone who's been working with and around coffee for a while
(he was a world barista champion in 2007[1])

He's recently been making a series called Weird Coffee Science[2], where he
looks at and tests scientific papers and weird ideas floating around.

[0]: [https://www.youtube.com/channel/UCMb0O2CdPBNi-
QqPk5T3gsQ](https://www.youtube.com/channel/UCMb0O2CdPBNi-QqPk5T3gsQ)

[1]: [https://youtu.be/_DwZV17bek4](https://youtu.be/_DwZV17bek4)

[2]:
[https://www.youtube.com/playlist?list=PLxz0FjZMVOl1Dmfogt84Q...](https://www.youtube.com/playlist?list=PLxz0FjZMVOl1Dmfogt84QKUxAKA6tu67K)

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riknos314
Beat me to it!

After watching that video I started microwaving my beans. It made such a huge
improvement in the quality of my pour-overs that I've never stopped.

For the extremely coffee curious: I typically brew a V60, 25g coffee, 1:16
ratio, beans microwaved 45 seconds on high (950W rated output microwave).
Baratza Virtuoso grinder.

~~~
groby_b
Not to nitpick - but none of that info has as big an influence on the taste of
your coffee as the one crucial bit you left out: What's the coarseness setting
of your Baratza?

(For comparison purposes, I usually use 30g coffee, 1:17, grinder at 19, V60,
205F water. Most of these I can fiddle quite a bit with before you really
notice, but the grinder setting really matters)

~~~
riknos314
I originally left that out as it can vary based on the density of the coffee
being used, and in addition grinders vary not only brand to brand, but quite a
bit between various grinders even of the same model. I've disassembled my
Baratza many times for repairs/cleaning, and changed the burrs once. I'm
fairly certain that I would get a noticeably different grind size than a brand
new Baratza Virtuoso at the same setting. That being said, here's the extra
details:

For my 25g, 1:16, I typically use around a 12 grind setting (can change +/\- 1
depending on the density of the coffee), and typically see around a 3m15s
total brew time including a 30 second bloom.

I typically brew light roast, and brew at a whopping 100C (212F), also at the
suggestion of James Hoffman - Info here:
[https://youtu.be/K_r5kpXPRYo](https://youtu.be/K_r5kpXPRYo)

~~~
sushid
@riknos314 and @groby_b, can you guys describe your pouring process? Do you
guys agitate your coffee? Do you guys continuous pour or pulse pour? If the
latter, what's the amount of water used for each pulse?

I do 25g, 1:14 w/ a bit of water to taste at 205 F, coarseness at 21 +/\- 1 on
an Encore with a V60. The reason I'm asking about your pour is I seem to get a
sludgy sediment for my final pulse if I do anything < 20, and even then my
extract time exceeds 3m unless I agitate with a stick.

I'm fairly certain nothing is wrong with my grinder (in fact I had an
unrelated reason and got it back from their repair center last week) and it's
still doing this so I'm betting it's my technique that's flawed.

~~~
groby_b
Sludgy sediment is usually an indicator of insufficient filtration. But while
coarseness does vary across machine, getting that at 21 indicates there's
something wrong - you shouldn't get _that_ fine of a grind.

I've been there, so maybe you made the same mistake that I made when I had
that problem: When you clean the Barratza and take out the white plastic
thingamabob, it goes back in two different ways, smoothly. But if your little
orange marker isn't towards the front, on the right hand side, your grind will
be _much_ too fine :)

I usually do an initial pour to allow the grounds to outgas - about 70-90
grams, pouring from the middle out, in a spiral.

Then two separate pours of ~220g, slow, outside in - I essentially use the
water to agitate the grounds a bit by rapidly pouring the last half in tight
circles at the center.

And for the people reading this and think "those coffee peeps are weird" \-
yes, we are. The taste differences are minute. Can't speak for others, but I
mostly do it because I like a ritual, I'm happy with any number of pour styles
as long as I get my coffee ;)

The reason I picked this particular ritual is because a) I swear it tastes
just a tiny bit better, and b) I learned it in a tiny coffee shop in Colombia
that I loved to pieces, and so every time I make coffee I'm reminded of that
trip.

~~~
sushid
Looks like the white plastic thing is in the right place. I'll try and up my
ratio and try the two pours of 220g tomorrow. Thanks! :)

~~~
groby_b
Measured total extraction time this morning, so you can compare - 30 seconds
for the first outgassing pour, 1:00 for the second pour (first 220g), 1:15 for
the third pour.

I usually pour without timer - since I don't like agitation, it's not like a
timer makes the water go faster :) - but that's pretty consistent with the
last time I measured. That was a total pour time of 2:52. (I keep lab notes. I
decided to just fully nerd out on my coffee a while ago)

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toomuchtuna
In the industry, this paper has long been known as 'the grinder paper'. Matt
Perger (one of the authors, and a World Brewers Cup champion) provides a good
layman's explanation: [https://www.baristahustle.com/blog/the-grinder-paper-
explain...](https://www.baristahustle.com/blog/the-grinder-paper-explained/)

~~~
simonebrunozzi
Nice. Are you in the industry, by any chance, or do you simply know about it?

Curious to see if you have other unknown things to share for a layman like me.

------
vvilliamperez
(2016)

