Does preheating the Cafelat Robot affect taste? Please post your experiences here! - Page 2

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mdmvrockford
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#11: Post by mdmvrockford »

Answer to your question DrGary:
Yes, preheating Cafelat Robot affects taste (positively).

DETAILS TO ABOVE ANSWER:
* My experience with Robot is limited. I received it 5/13/2021 and typically only drink at most two double espressos per day.

* My preheat of Robot is as follows: portafilter and professional basket in thick glass bowl filled with boiling water; ceramic mug filled boiling water to heat the piston. Former (PF and basket) heated for at least three minutes while do other drink prep. The latter (piston) heated for at least 90 seconds.

* Beans brewed so far (a) Dark Matter Unicorn blood (blend and no clue of its components) (b) home roast (Scott Rao Full City ) by fellow home-barista member of El Salvador Finca Kilimanjaro.

* Grinder is Helor 106 with Mazzer 71mm single phase conical burr

* Dosing is 17 grams bean and 22 grams drink for the Unicorn Blood. For the Finca Kilimanjaro it is 20 grams bean and 55 grams drink.

* Compared to no preheat, I much prefer preheat for these two particular bean roasts. Testing was not blinded but comparing tasting notes. A little too much acidity for my liking with the Finxa Kilimanjaro w/o preheat. It could be bias but better flavor separation for the Unicorn Blood with preheating.

* I plan to do blinded testing preheat vs. no preheat with a couple of the Chicago-Milwaukee sages on next meet up.

* Yes DrGary, I feel like I am reinventing the heating wheel that will end up at a closed boiler:) But with above routine, it isn't too bad. I am sure Paul Pratt would be shaking his head in disbelief, LOL.
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drgary (original poster)
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#12: Post by drgary (original poster) »

Of course, the intention here is to drive Paul crazy. Paul, have we succeeded yet?

As I read the replies so far, I would love to see tasting notes for different types of preheating.
Gary
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jpender
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#13: Post by jpender »

grind727 wrote:...I'm not doubting the general relationship between brew temperature and taste, as I know it matters, but based on my own experience, I'm skeptical that preheating various bits of the Robot makes much difference in the cup.
The whole notion of a thread specific to the Robot begs this question. But why? Why would the Robot somehow make coffee insensitive to brew temperature?

grind727 wrote:I tend to pour and press pretty quickly after the kettle boils, so maybe that's a factor?
Not really. I mean, if you're slow enough it gets colder but when there's cold metal to heat up you can't pour fast enough to change that.

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#14: Post by grind727 »

jpender wrote:The whole notion of a thread specific to the Robot begs this question. But why? Why would the Robot somehow make coffee insensitive to brew temperature?
I'm not saying it makes the coffee insensitive to brew temperature, I'm just wondering if preheating the Robot really impacts brew temperature enough to matter, enough to noticeably impact taste.

With the Robot, brew water is pushed through a relatively thin screen and basket. Is there really that much time and thermal mass to make a difference if you pour and press with little delay?

I'm skeptical, but I seem to be in the minority here. I've also never done a blind tasting, so I appreciate hearing from those of you who have.
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#15: Post by VoidedTea »

I would like to throw a little psychology into the mix which I believe might be directly related to the question asked. As most of you well aware, our brain often does some "editing" to our perception of reality, but as a result making it more distorted than it is. A huge moon at the horizon is purely a "photoshop" of our brain and in reality is exactly the same size as when it moves up high in the sky. Add a shadow to a white object on a picture and our brain will immediately change its colour to grey. The brain works by associations constantly adjusting our perceptions depending on registered information. How does it relate to coffee? Well, if you managed to create an association in your brain between pre-heating ritual and "better taste", the coffee will always taste better with preheating after that. Not because it really is, but because your brain makes you feel it is. And now you are destined to pre-heating unless you find the way to break that association. Which is probably almost impossible. It is like trying to make that moon appear smaller at the horizon. Impossible. So what I am trying to say is that we should be careful debating this subject due to the phenomenon of associative distortion of reality caused by our not so perfect brain. Preheating of PF might have a very negligible change in real water physics and coffee chemistry if measured by equipment, yet our brain may elevate this negligible change to a much higher level due to embedded associations. Just be aware of that. The only way to prove the existence of difference in taste is a blind test when the tester doesn't know which cup is which to avoid the impact of associative perception, but chances are not that many people in this group conducted such tests.

A disclaimer - I am not a professional psychologist but enjoy reading about brain functions as a hobby. Feel free to correct my understanding of the subject in any way.

mdmvrockford
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#16: Post by mdmvrockford »

No surprise here: for light roasted beans that really have no business being brewed as espresso, preheating the Robot helps.
It tamed the acidity and flavors less harsh.

I will be off this weekend to Chicago to find a known-to-me medium to dark espresso roast to see how preheat effects on taste. And will be taking Robot with me as more portable than (former) Cremina or my Alexia.


Details to above:
Last night, I opened new coffee for Boss' Clever Coffee Dripper: George Howell Ethiopia Guduba. Bag says "light roast". IIRC, their customer service said it is ColorTrack 45. Based on grinding effort on hand-powered grinder it is a light roast. But not a light as say years ago Ethiopia Yirghacheffe that had Agtron 75. I usually just brew one or two double espressos from such roasts; pure curiosity and challenge. Remainder of the roast will be brewed as it was intended: as regular brew and here Clever Coffee Dripper.
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#17: Post by jpender »

grind727 wrote:I'm not saying it makes the coffee insensitive to brew temperature, I'm just wondering if preheating the Robot really impacts brew temperature enough to matter, enough to noticeably impact taste.

With the Robot, brew water is pushed through a relatively thin screen and basket. Is there really that much time and thermal mass to make a difference if you pour and press with little delay?

I'm skeptical, but I seem to be in the minority here. I've also never done a blind tasting, so I appreciate hearing from those of you who have.

How much of a temperature difference does there need to be to affect the taste? That's a general question, one not specific to the Robot. And I think the answer isn't simple. I believe it depends on the coffee and on other brewing parameters.

I understand the psychological argument. And I also know that there are other sources of variation from shot to shot that can fool one into thinking that a particular change makes a difference. Nonetheless, I have seen a pattern where in some cases preheating makes things worse and in other cases it improves the taste. And, to fuel skepticism, I've also experienced times when it didn't seem to have much effect, if any.

This morning I pulled two shots as identically as I could. The first was with the Robot stone cold. The second I preheated it fully (piston, portafilter, basket, screen). I have a temperature sensor embedded in my Robot, dangling below the piston so that it is immersed in the water during the shot. Here is what it reported:




I put a cover over the first shot while I pulled the second. Then I added a measured amount of hot water to each. Since the first was a few degrees cooler I put it in the microwave for 5 seconds to equalize them at about 65°C. Then I randomized them: identical cups with marks on the bottom. And I tasted them, not knowing which was which.

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drgary (original poster)
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#18: Post by drgary (original poster) »

And the result was ... ? (In this thread the homework assignment is to tell us how it tasted. :roll: )

BTW I think the microwaving changes what you brewed. I would take it to room temperature without the microwave.
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#19: Post by Chrikelnel »

I went to go try it this morning and then realized I only had enough coffee left for one shot, and my new bag is only 3 days off roast so probably not a fair test. I'll attempt it again once my coffee is a bit more off roast.

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#20: Post by jpender »

drgary wrote:BTW I think the microwaving changes what you brewed. I would take it to room temperature without the microwave.
Why? Is there something about microwave radiation that affects coffee adversely? Or are you objecting to the shot being heated up 2-3°C?