James Hoffmann Aeropress Extravaganza - Page 7

Coffee preparation techniques besides espresso like pourover.
nameisjoey

#61: Post by nameisjoey »

jpender wrote:he also used the phrases "ultimate Aeropress technique" and "my perfect technique". So there's a mixed message.
For what it's worth all of his personal techniques that he uses himself and shares with us get the "ultimate technique" name - its essentially how he brands his techniques/recipes for all brew methods. Just in the same way his v60 isn't the end all be all but it's a simple way to get excellent coffee from that brew method. His conclusion wasn't that preheating doesn't matter at all - but that to his tastes for his brewing recipe he could not taste a difference.

I really think you're over thinking it all man. His goal is to make the simplest recipe to get consistently good coffee and cut out any unnecessary fluff. So for him rinsing/stirring/preheating doesn't make a discernible difference in the cup so he cuts them out. He's not wrong, because at the end of the day he couldn't taste a difference. It's really as simple as that. Just like if you can taste a difference so you do those steps, you aren't wrong either :)

DamianWarS
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#62: Post by DamianWarS »

jpender wrote:He concluded that because his singular test of preheating showed little difference. What I'm saying is that he didn't look hard enough. Whatever his protocol was it missed an obvious effect. Now you could argue that the temperature difference is still not large enough to matter but that's not what he said. He said, basically, there's almost no difference in the temperature so no reason to bother.




You be the judge:

image




That's a good point. I agree with you. Hoffmann covered a lot of ground but didn't delve very deep and overgeneralized his results. To his credit he was upfront about how his approach isn't the last word. But he also used the phrases "ultimate Aeropress technique" and "my perfect technique". So there's a mixed message.
Great graphs. What probes do you use to get those results and how do you complie them? I'm interest in doing similar stuff but don't have the tools yet. I've heard you can use roasting software like artisan to get a live graph output.

I would be interested in knowing what preheated no coffee looks like with some sort of lid to stop the heat from escaping (like a polystyrene cover). Your preheat just water and no preheat with coffee seems to drop at the same rate. Does this suggest the absorption of heat through the plastic is the same rate of heat escaping out the top? It seems odd to me they would be so similar with their rate of drop. What does a no preheat and just water look like? Based on your graph it should drop double the rate.

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jpender

#63: Post by jpender »

nameisjoey wrote:His conclusion wasn't that preheating doesn't matter at all - but that to his tastes for his brewing recipe he could not taste a difference.
He didn't do a taste test. He simply measured the temperatures, noted that they were nearly the same, made up an explanation for that, and concluded that "from a brew temperature perspective" it wasn't necessary to preheat.

If he can taste the difference between a stir and a swirl and has opinions about the best temperature for a given roast level then it's not a stretch to imagine he could also taste the difference between coffees brewed with these two temperature profiles:


jpender

#64: Post by jpender »

DamianWarS wrote:What probes do you use to get those results and how do you complie them?
I've been using 0.1°C precision thermistors that I coat with a thin layer of epoxy to waterproof. I put together a little data logger using a stock Arduino and a piggyback board that has an SD card, an added A/D convertor, a small display screen, and a couple of buttons. For graphing I just use Excel. This particular thermistor reads a little low near boiling but I'm not so concerned with absolute temperature for these tests. I want to know the relative effects.

DamianWarS wrote:I would be interested in knowing what preheated no coffee looks like with some sort of lid to stop the heat from escaping (like a polystyrene cover). Your preheat just water and no preheat with coffee seems to drop at the same rate. Does this suggest the absorption of heat through the plastic is the same rate of heat escaping out the top? It seems odd to me they would be so similar with their rate of drop. What does a no preheat and just water look like? Based on your graph it should drop double the rate.
I measured evaporation to be about 0.2g after 90s for the coffee & water case. For water only it ranged from 0.6 to 1.0g. Losing a gram of water to evaporation translates into a temperature loss of roughly 2°C. Of course there is also convective loss to the air. And probably a bunch of heat is lost during the pour. It's complicated. I can't pretend to model it.

Here are graphs of water-only pours, preheated vs non-preheated, open top vs a fitted ensolite lid. The lid was not 100% air tight though. I could feel some warm air sneaking around the edges and measured a little over 0.1g loss.




To make it easier to compare heat loss rates here are the same traces aligned in temperature:


ohwhen

#65: Post by ohwhen »

I also again thought that the preheated brew tasted different (better). Since I brewed the cups sequentially I heated up the first in the microwave so that they were both the same (just a little under 60°C). Tasting, I still had the same impression. So then I poured a little of each into identical cups, one with a hidden mark. Then I rotated them in a salad spinner to randomize. It was easy to pick the preheated one. Of course there could be other reasons besides the temperature for why they tasted different.
You reheated a coffee for a taste test in the microwave?

jpender

#66: Post by jpender »

ohwhen wrote:You reheated a coffee for a taste test in the microwave?
Yeah, it's not ideal but I thought temperature equivalence was important for a side by side test. If it made it worse it wasn't by much as it was still better than the unreheated cup. Or are you wondering if reheating might have improved it?

ohwhen

#67: Post by ohwhen »

No, I doubt it made it better-just wanted to clarify as I was surprised. Side by side home tests are hard if you only have one kettle/device. I either try to let stuff sit to equalize in temp a bit (never works out) or take tasting notes at specific temps to compare. Are you only using one aeropress? Are you washing in between brews or just rinsing? Is the rinsing/washing protocol your using the same one you use when you're doing brewing a cup of coffee to drink?

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jpender

#68: Post by jpender »

ohwhen wrote:Are you only using one aeropress? Are you washing in between brews or just rinsing? Is the rinsing/washing protocol your using the same one you use when you're doing brewing a cup of coffee to drink?
I only own one Aeropress. Usually I start with a clean Aeropress at room temperature. After brewing I rinse it and set it to dry or towel it off if I'm going to make another cup right away.

For each of these tests I cooled the Aeropress down to 16°C by submerging it in a water bath and then dried it completely. That way for each test the Aeropress started at the same temperature. But even with that it was kind of a sloppy set of tests since the water amounts weren't exactly same and I didn't adjust for the absence of coffee in the water-only tests. I wasn't really trying to get exact numerical results. I just wanted to see roughly how much of an effect there was.

Jonk

#69: Post by Jonk »

ohwhen wrote:You reheated a coffee for a taste test in the microwave?
There's a video on that as well 8)
Definitely agree on the difficulty of doing side by side testing. Even with two devices and more than one person, it's not so easy to pull off two identical brews. Even cupping is not ideal. A bunch of ember mugs might be a solution but talk about expensive.

DamianWarS
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#70: Post by DamianWarS »

Jonk wrote:There's a video on that as well 8)
video

Definitely agree on the difficulty of doing side by side testing. Even with two devices and more than one person, it's not so easy to pull off two identical brews. Even cupping is not ideal. A bunch of ember mugs might be a solution but talk about expensive.
Thermal carafes/tumblers should be fine while the coffee is waiting for the next brew. You can brew right into them and then close the lid.