Phobic wrote:- Over extracting in immersion is hard to do - Matt's lecture suggests you need to boil the grinds with water in a pan!

This is popular notion nowadays. But it's certainly quite possible to get bitter, astringent flavors in an immersion brew without boiling it. Jonathan Gagné even mentions this in his ultimate Aeropress recipe description.

In that video, Matt Perger says that if you get those flavors it generally means the coffee wasn't roasted very well. Maybe so, but if that's the case then there is a lot of coffee that isn't up to his standards. The coffee I used this morning, for example. Perger says with a good coffee you should be able to pull 1:16 in an espresso machine and get great coffee. I can't even pull 1:2 with the coffee I have right now. So, by his definition, it's poorly roasted. But it tastes great when pulled shorter. So I believe he is spinning the idea "you can't overextract". I wonder if he is talking mainly about very lightly roasted coffees.

Glad this popped back up. I actually did something similar to the OP a few days ago while dialing in my SSP burrs on the Ode for Aeropress. I did three different brews at 2, 3, an 4 setting. I use the inverted method with a 2 min steep before a 30s plunge for a total contact time of 2:30. I usually use around 92-94C water temp unless it is light then I go off boil. On my palate, I felt a bit more astringency at 2. Not really bitter as much just slightly unpleasant drying. The 4 felt like it had less body but the most clarity. I enjoyed 4 the most but it really was nit picking. All could easily be served to someone and would have been a great cup of coffee. I too was surprised how little the large swing in grind size made.

It seems like as long as you are in the ballpark then it is a matter of tweaking just a bit here and there for personal taste. Interestingly... I did an Aeropress of the SSP Ode and a super cheap Amazon Chinese Fuji-copy grinder with gnarly looking burrs. The difference wasn't as appalling as you'd think. More clarity in the Aeropress but the cheapo grinder wasn't bad at all. We really are talking about minor differences when using an Aeropress.

jpender wrote:This is popular notion nowadays. But it's certainly quite possible to get bitter, astringent flavors in an immersion brew without boiling it. Jonathan Gagné even mentions this in his ultimate Aeropress recipe description.

certainly that's my expectation as well, not sure if I'm going to be able to address it at this grind level by just reducing the steep time, I would think I could - whether it's a better cup at the end is the question!

jpender wrote:In that video, Matt Perger says that if you get those flavors it generally means the coffee wasn't roasted very well.

The main issue I think he's calling out is the roasting equipment capability and then the roasters ability, the example he uses is this can lead to beans which are over roasted on the outside but under roasted on the inside - which effectively gives a similar problem to wide standard deviation grind sizes i.e. bits of the grind will over extract while others will under extract.

this makes sense in my head, but I don't know enough about roasting to comment on how wide spread an issue this is. I'd have thought it's a bigger issue with lighter roasts because the range of roast level through the bean will be bigger versus a darker roast. (but I'm just guessing!).

jpender wrote:Maybe so, but if that's the case then there is a lot of coffee that isn't up to his standards. The coffee I used this morning, for example. Perger says with a good coffee you should be able to pull 1:16 in an espresso machine and get great coffee. I can't even pull 1:2 with the coffee I have right now. So, by his definition, it's poorly roasted. But it tastes great when pulled shorter. So I believe he is spinning the idea "you can't overextract".

isn't he saying that where you have a very narrow std deviation on the grind though, where you don't I can't see how you're not over extracting part of the distribution - we're just trying to max the total extraction by blending the extraction throughout the grind range.

jpender wrote:I wonder if he is talking mainly about very lightly roasted coffees.

will have to check but IIRC is was all roasts but more so with lighter