Coffee Ad Astra
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Coffee brewing tips for the geekiest

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I have now made public a blog post in which I discuss the effect of grind size on extraction yield and the taste of filter coffee ! You can find it here:
https://coffeeadastra.com/2020/04/02/why-cant-we-grind-coffee-finer-for-pour-over/

My next blogpost is a big one, and just became available for my Patreon backers. It goes deep into the physics of kettle streams and agitation, with practical recommendations on pour rate and height that will maximize the evenness of extraction. It will become public when I release my next blog post, as usual.
I just tried a simpler version of Rao/Perger water with less minerals and the same KH, GH and Mg/Ca ratio. It has a bit more sodium but seems to taste good so far, and the concentrate doesn’t precipitate as much (it still does). If anyone wants to try it I’d love to hear your thoughts !

Here’s the concentrate recipe:
13g epsom salt
2.98g sodium bicarbonate
2.64g CaCl2 anhydrous (small white balls)

Fill up to 350g with distilled water (hot water makes it faster).

Use 4g/L concentrate in distilled water.
Hey all, my apologies, in my last post I wrote down the wrong water recipe 😓 that one was for a half-buffer water, which I find produces brews that are a bit too sour. Here's the actual recipe with the same KH and GH as Rao/Perger !

13g epsom salt
5.95g sodium bicarbonate
2.64g CaCl2 anhydrous (small white balls)

Fill up to 350g with distilled water (hot water makes it faster).

Use 4g/L concentrate in distilled water.

Thanks Geshapacamara for pointing this out !
My blog post on the physics of kettle streams is now available on my blog !
https://coffeeadastra.com/2020/05/23/the-physics-of-kettle-streams/

I’m very happy about this one, and it took quite a bit of digging through the scientific literature to put it together !

My next blog post, available now on Patreon (https://www.patreon.com/coffeeadastra) and on my public blog later, is about how different coffee varieties, processing and origin countries affect the average extraction yield and brew time !
Coffee Ad Astra pinned «My blog post on the physics of kettle streams is now available on my blog ! https://coffeeadastra.com/2020/05/23/the-physics-of-kettle-streams/ I’m very happy about this one, and it took quite a bit of digging through the scientific literature to put it…»
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Hey all! If you want to learn about my astrophysics research, I just wrote my first blog post about it!

https://jgagneastro.com/2020/06/18/a-giant-group-of-siblings-to-the-big-dipper-stars/

There’s even a french version!
I just publicly released my blog post about the effects of coffee varieties, origins and processing !

https://bit.ly/2FSeXmo

It contains a discussion of how these properties of coffee beans affect average extraction yield and brew time, based on 416 V60 brews with 192 coffee bags that I logged over the past year or two.

This is also a preview of the kind of stuff you will soon be able to read in my upcoming book "The Physics of Filter Coffee", which is in the designing stage and is slated for publication this December. Pre-orders are not yet available.

My next blog post will be about how I brew with the Fellow Stagg [X] dripper, with a brew video. It is already available for my Patreon backers. For the past 6 months, I completely switched from the V60 to the Stagg [X], as I find it produces sweeter and more evenly extracted coffee. In the post, I also show some data about how it differs from the V60 and why I believe it produces better extractions.
I just tried Steady State under recommendation by Scott, and I'm very happy with my order. My favorites so far are the Kenya Rungeto and Colombia Indestec El Paraiso. I need to brew it a bit more but Nensebo Refisa also shows great promise! PS The Renguto is the best Kenyan I've tried this year.
This Friday October 9th at 4 PM (EST), I'll do a live chat with Scott Rao on Instagram! We'll answer coffee questions that he received, some that we will receive live, and we will talk about my upcoming book "The Physics of Filter Coffee"! Join us, this will be fun!